Editing Green (section)

== In science ==
{| class="wikitable floatright" style="text-align:center"
|-
!colspan="3" style="background:#FFF;"| [[File:Linear visible spectrum.svg|center|240px|sRGB rendering of the spectrum of visible light]]
|-
! [[Color|Colour]]
! [[Frequency]]<br />([[terahertz radiation|THz]])
! [[Wavelength]]<br />([[Nanometre|nm]])
|-
|style="text-align:left"| {{legend|#7f00ff|[[violet (color)|'''violet''']]}}
| 668–789
| 380–450
|-
|style="text-align:left"| {{legend|blue|'''[[blue]]'''}}
| 610–668
| 450–490
|-
|style="text-align:left"| {{legend|cyan|'''[[cyan]]'''}}
| 575–610
| 490–520
|-
|style="text-align:left"| {{legend|lime|'''green'''}}
| 526–575
| 520–570
|-
|style="text-align:left"| {{legend|yellow|'''[[yellow]]'''}}
| 508–526
| 570–590
|-
|style="text-align:left"| {{legend|orange|'''[[orange (colour)|orange]]'''}}
| 484–508
| 590–620
|-
|style="text-align:left"| {{legend|red|'''[[red]]'''}}
| 400–484
| 620–770
|}

=== Color vision and colorimetry ===
In optics, the [[perception]] of green is evoked by light having a spectrum dominated by energy with a [[wavelength]] of roughly 495–570&nbsp;[[Nanometre|nm]]. The sensitivity of the dark-adapted human eye is greatest at about 507&nbsp;nm, a blue-green color, while the light-adapted eye is most sensitive about 555&nbsp;nm, a yellow-green; these are the peak locations of the rod and cone (scotopic and photopic, respectively) [[luminosity function]]s.<ref>{{cite web
 | title = Human vision and color perception
 | website = Olympus Microscopy
 | department = Resource center
 | url = http://www.olympusmicro.com/primer/lightandcolor/humanvisionintro.html
 | access-date = 19 September 2007
 | archive-date = January 15, 2011
 | archive-url = https://web.archive.org/web/20110115040551/http://www.olympusmicro.com/primer/lightandcolor/humanvisionintro.html
 | url-status = dead
 }}</ref>

The perception of greenness (in opposition to redness forming one of the [[opponent process|opponent]] mechanisms in human [[color vision]]) is evoked by light which triggers the medium-wavelength ''M'' [[cone cell]]s in the eye more than the long-wavelength ''L'' cones. Light which triggers this greenness response more than the yellowness or blueness of the other color opponent mechanism is called green. A green light source typically has a spectral power distribution dominated by energy with a wavelength of roughly 487–570&nbsp;nm.{{efn|
More specifically, "blue green" 487–493&nbsp;[[Nanometre|nm]], "bluish green" 493–498&nbsp;nm, "green" 498–530&nbsp;nm, "yellowish green" 530–559&nbsp;nm, "yellow green" 559–570&nbsp;nm Kelly (1943).<ref>
{{cite journal
 | last1 = Kelly | first1 = Kenneth L.
 | year = 1943
 | title = Color designations for lights
 | journal = [[Journal of the Optical Society of America]]
 | volume = 33 | issue = 11| pages = 627–32
 | doi=10.1364/josa.33.000627
| bibcode = 1943JOSA...33..627K
 }}
</ref>
}}
[[File:RGB illumination.jpg|left|thumb|Red. green, blue ed are [[additive colors]]. All the colors seen are made by mixing them in different intensities.]]
Human eyes have color receptors known as cone cells, of which there are three types. In some cases, one is missing or faulty, which can cause [[color blind]]ness, including the common inability to distinguish red and yellow from green, known as [[deuteranopia]] or red-green color blindness.<ref name=brit>
{{cite encyclopedia
 |title=Color blindness
 |year=2002
 |encyclopedia=The New Encyclopædia Britannica
 |place=Chicago, IL
 |publisher=Encyclopædia Britannica Co.
 |isbn=0-85229-787-4
}}
</ref>
Green is restful to the eye. Studies show that a green environment can reduce fatigue.<ref>
{{cite journal
 |last=Laird |first=Donald A.
 |date=Sep 1933
 |title=Fatigue: Public enemy number one: What it is and how to fight it
 |journal=The American Journal of Nursing
 |volume=33 |issue=9 |pages=835–841
}}
</ref>

In the [[subtractive color]] system, used in painting and color printing, green is created by a combination of yellow and blue, or yellow and [[cyan]]; in the [[RGB color model]], used on television and computer screens, it is one of the [[additive primary colors]], along with red and blue, which are mixed in different combinations to create all other colors. On the [[HSV color space|HSV color wheel]], also known as the [[:File:RBG color wheel.svg|RGB color wheel]], the [[Complementary color|complement]] of green is [[magenta]]; that is, a color corresponding to an equal mixture of [[red]] and [[blue]] light (one of the [[purple]]s). On a traditional color wheel, based on subtractive color, the complementary color to green is considered to be red.<ref name=wheel>
{{cite web
 |title=Color wheel
 |year=2005
 |department=Glossary term
 |publisher=Sanford Corp.
 |url=http://www.sanford-artedventures.com/study/g_color_wheel.html
  |access-date=22 November 2007
 |archive-url = https://web.archive.org/web/20070928021215/http://www.sanford-artedventures.com/study/g_color_wheel.html
 |archive-date=28 September 2007
}}
</ref>

In additive color devices such as computer displays and televisions, one of the [[primary colors|primary]] light sources is typically a narrow-spectrum yellowish-green of dominant wavelength ≈550&nbsp;[[Nanometre|nm]]; this "green" primary is combined with an orangish-red "red" primary and a purplish-blue "blue" primary to produce any color in between – the RGB color model. A [[unique hues|unique green]] (green appearing neither yellowish nor bluish) is produced on such a device by mixing light from the green primary with some light from the blue primary.

=== Lasers ===
[[Image:Starfire Optical Range - three lasers into space.jpg|right|thumb|Three green lasers being fired at a single spot in the sky from the [[Starfire Optical Range]]]]

[[Laser]]s emitting in the green part of the spectrum are widely available to the general public in a wide range of output powers. Green laser pointers outputting at 532&nbsp;[[Nanometre|nm]] (563.5&nbsp;[[terahertz radiation|THz]]) are relatively inexpensive compared to other wavelengths of the same power, and are very popular due to their good beam quality and very high apparent brightness. The most common green lasers use diode pumped solid state ([[DPSS]]) technology to create the green light.<ref name=laserglow>
{{cite web
 |title=Green lasers
 |website=Laserglow (Laserglow.com)
 |url=http://www.laserglow.com/page/greenlaserpointer
 |access-date=27 September 2011
}}
</ref>
An infrared [[laser diode]] at 808&nbsp;nm is used to pump a crystal of neodymium-[[Doping (semiconductor)|doped]] yttrium vanadium oxide (Nd:YVO4) or neodymium-doped yttrium aluminium garnet (Nd:YAG) and induces it to emit 281.76 THz (1064&nbsp;nm). This deeper infrared light is then passed through another crystal containing potassium, titanium and phosphorus (KTP), whose non-linear properties generate light at a frequency that is twice that of the incident beam (563.5 THz); in this case corresponding to the wavelength of 532&nbsp;nm ("green").<ref name="Sams Laser FAQ">
{{cite web
 |title=Sam's laser FAQ
 |website=donklipstein.com
 |publisher=Sam Goldwasser
 |url=http://donklipstein.com/laserssl.htm
 |access-date=27 September 2011
}}
</ref>
Other green wavelengths are also available using DPSS technology ranging from 501&nbsp;nm to 543&nbsp;nm.<ref name=laserglow2>
{{cite web
 |title=DPSS lasers
 |website=Laserglow (Laserglow.com)
 |url=http://www.laserglow.com/int-labOEM.htm 
 |access-date=27 September 2011
}}
</ref>
Green wavelengths are also available from [[gas laser]]s, including the [[helium–neon laser]] (543&nbsp;nm), the Argon-[[ion laser]] (514&nbsp;nm) and the Krypton-ion laser (521&nbsp;nm and 531&nbsp;nm), as well as liquid [[dye laser]]s. Green lasers have a wide variety of applications, including pointing, illumination, surgery, [[laser light shows]], [[spectroscopy]], [[interferometry]], [[fluorescence]], [[holography]], [[machine vision]], [[non-lethal weapons]], and [[bird control]].<ref name=laserglow3>{{cite web
 |title=Green lasers for bird control / abatement
 |website=Laserglow (Laserglow.com)
 |url=http://www.laserglow.com/page/golfcoursebirdcontrol
 |access-date=27 September 2011
 |archive-date=August 7, 2020
 |archive-url=https://web.archive.org/web/20200807160555/https://www.laserglow.com/page/golfcoursebirdcontrol
 |url-status=dead
 }}</ref>

As of mid-2011, direct green laser diodes at 510&nbsp;nm and 500&nbsp;nm have become generally available,<ref>
{{cite web
 |title=Review: 510&nbsp;nm direct green diodes / Build Photos (DGH-N1, DGH-N2)
 |date=13 December 2011
 |department=Discuss Laser Pointers
 |website=Laser Pointer Forums (laserpointerforums.com)
 |url=http://laserpointerforums.com/f45/review-510nm-direct-green-diodes-build-photos-dgh-n1-dgh-n2-69678.html
 |access-date=March 17, 2016
}}
</ref>
although the price remains relatively prohibitive for widespread public use. The efficiency of these lasers (peak 3%){{citation needed|date=August 2013}} compared to that of DPSS green lasers (peak 35%){{citation needed|date=August 2013}}<ref>
{{cite journal
 |last=Davarcioglu  |first=Burhan
 |date=December 2010
 |title=An overview of diode pumped solid state (DPSS) lasers
 |journal=International Archive of Applied Sciences and Technology
 |volume=1 |pages=1–12
 |url=https://www.researchgate.net/profile/Al_Timimi_Zahra/post/What_are_the_limtations_of_using_diode_laser_for_pumping_some_lasers/attachment/5d8ca3b93843b0b982663797/AS%3A807347454758914%401569498041146/download/1.pdf
 |via=researchgate.net
}}
</ref>
may also be limiting adoption of the diodes to niche uses.

=== Pigments, food coloring and fireworks ===
{{See also|Green pigments}}
[[File:Chicago River dyed green, focus on river.jpg|thumb|The [[Chicago River]] is dyed green every year to mark [[St. Patrick's Day]]]]
Many minerals provide [[pigment]]s which have been used in green paints and dyes over the centuries. Pigments, in this case, are minerals which reflect the color green, rather that emitting it through [[luminescent]] or [[phosphorescent]] qualities. The large number of green pigments makes it impossible to mention them all. Among the more notable green minerals, however is the [[emerald]], which is colored green by trace amounts of [[chromium]] and sometimes [[vanadium]].<ref>
{{cite book
 |last1=Hurlbut    |first1=Cornelius S. Jr
 |last2=Kammerling |first2=Robert C.
 |year=1991
 |title=Gemology
 |page=203
 |publisher=John Wiley & Sons
 |place=New York, NY
}}
</ref>
Chromium(III) oxide (Cr<sub>2</sub>O<sub>3</sub>), is called [[Chromium(III) oxide|chrome green]], also called [[viridian]] or institutional green when used as a pigment.<ref name=Holleman-Wiberg-2001/> For many years, the source of [[amazonite]]'s color was a mystery. Widely thought to have been due to [[copper]] because copper compounds often have blue and green colors, the blue-green color is likely to be derived from small quantities of [[lead]] and water in the [[feldspar]].<ref>
{{cite journal
 | author1=Hoffmeister
 | author2=Rossman
 | year=1985
 | title=A spectroscopic study of irradiation coloring of amazonite; structurally hydrous, Pb-bearing feldspar
 | journal=[[American Mineralogist]]
 | volume=70 | pages=794–804
}}
</ref>
Copper is the source of the green color in [[malachite]] pigments, chemically known as basic [[copper(II) carbonate]].<ref>
{{cite web
 | title = Malachite
 | year = 2001
 | website = WebExhibits
 | url = http://webexhibits.org/pigments/indiv/overview/malachite.html
 | access-date = December 8, 2007
}}
</ref>

[[Verdigris]] is made by placing a plate or blade of copper, brass or bronze, slightly warmed, into a vat of fermenting wine, leaving it there for several weeks, and then scraping off and drying the green powder that forms on the metal. The process of making verdigris was described in ancient times by [[Pliny the Elder|Pliny]]. It was used by the Romans in the murals of Pompeii, and in Celtic medieval manuscripts as early as the 5th century AD. It produced a blue-green which no other pigment could imitate, but it had drawbacks: it was unstable, it could not resist dampness, it did not mix well with other colors, it could ruin other colors with which it came into contact, and it was [[toxic]]. [[Leonardo da Vinci]], in his treatise on painting, warned artists not to use it. It was widely used in miniature paintings in Europe and Persia in the 16th and 17th centuries. Its use largely ended in the late 19th century, when it was replaced by the safer and more stable [[chrome green]].{{sfn|Varichon|2000|pp=214–15}} Viridian, as described above, was [[patent]]ed in 1859. It became popular with painters, since, unlike other synthetic greens, it was stable and not toxic. [[Vincent van Gogh]] used it, along with [[Prussian blue]], to create a dark blue sky with a greenish tint in his painting ''[[Café Terrace at Night]]''.<ref name=Holleman-Wiberg-2001/>

[[Green earth]] is a natural pigment used since the time of the [[Roman Empire]]. It is composed of clay colored by [[iron oxide]], [[magnesium]], [[aluminum silicate]], or [[potassium]]. Large deposits were found in the South of France near [[Nice]], and in Italy around [[Verona]], on [[Cyprus]], and in [[Bohemia]]. The clay was crushed, washed to remove impurities, then powdered. It was sometimes called Green of Verona.{{sfn|Varichon|2000|pp=210–11}}

Mixtures of oxidized [[cobalt]] and [[zinc]] were also used to create green paints as early as the 18th century.<ref>
{{cite web
 | title = Cobalt green
 | year = 2001
 | website = WebExhibits
 | url = http://webexhibits.org/pigments/indiv/overview/cogreen.html
 | access-date = December 8, 2007
}}
</ref>

[[Cobalt green]], sometimes known as [[Cobalt green#Rinman's green|Rinman's green]] or zinc green, is a translucent green pigment made by heating a mixture of cobalt (II) oxide and zinc oxide. [[Sven Rinman]], a Swedish chemist, discovered this compound in 1780.<ref>
{{cite news
 |title = Green pigment spins chip promise
 |date = 9 August 2006
 |website = [[BBC News]]
 |url = http://news.bbc.co.uk/2/hi/technology/4776479.stm
}}
</ref>
Green chrome oxide was a new synthetic green created by a chemist named Pannetier in Paris in about 1835. Emerald green was a synthetic deep green made in the 19th century by hydrating chrome oxide. It was also known as Guignet green.<ref name=Holleman-Wiberg-2001>
{{cite book
 |first1=A.F. |last1=Holleman 
 |first2=E.   |last2=Wiberg
 |year=2001
 |title=Inorganic Chemistry
 |publisher=[[Academic Press]]
 |place=New York, NY
}}
</ref>

[[File:Fireworks 2.JPG|thumb|left|[[Fireworks]] typically use [[barium]] salts to create green sparks]]
There is no natural source for green [[food coloring]]s which has been approved by the US [[Food and Drug Administration]]. Chlorophyll, the [[E number]]s E140 and E141, is the most common green chemical found in nature, and only allowed in certain medicines and cosmetic materials.<ref>
{{cite magazine
 | first = Victoria | last = Gilman
 | date = 25 August 2003
 | title = Food coloring: Synthetic and natural additives impart a rainbow of possibilities to the foods we eat
 | magazine = [[Chemical & Engineering News]]
 | url = http://pubs.acs.org/cen/whatstuff/stuff/8134foodcoloring.html
 | access-date = December 8, 2007
}}
</ref>
[[Quinoline Yellow WS|Quinoline Yellow]] (E104) is a commonly used coloring in the United Kingdom but is banned in Australia, Japan, Norway and the United States.<ref>
{{cite web
 | url = http://www.ukfoodguide.net/e104.htm
 | archive-url = https://web.archive.org/web/20030508004821/http://www.ukfoodguide.net/e104.htm
 | url-status = usurped
 | archive-date = May 8, 2003
 | title = E104 Quinoline Yellow, FD&C Yellow No.10
 | website = UK Food Guide
 | access-date = 9 December 2007
}}
</ref>
[[Green S]] (E142) is prohibited in many countries, for it is known to cause [[hyperactivity]], [[asthma]], [[urticaria]], and [[insomnia]].<ref>
{{cite web
 | title = E142 Green S
 | website = UK Food Guide
 | url = http://www.ukfoodguide.net/e142.htm
 | archive-url = https://web.archive.org/web/20030511014619/http://www.ukfoodguide.net/e142.htm
 | url-status = usurped
 | archive-date = May 11, 2003
 | access-date = 9 December 2007
}}
</ref>

To create green sparks, [[firework]]s use [[barium]] [[Salt (chemistry)|salts]], such as [[barium chlorate]], [[barium nitrate]] crystals, or [[barium chloride]], also used for green fireplace logs.<ref name=firework/> Copper salts typically burn blue, but [[cupric chloride]] (also known as "campfire blue") can also produce green flames.<ref name=firework/> Green pyrotechnic flares can use a mix ratio 75:25 of [[boron]] and [[potassium nitrate]].<ref name=firework/> Smoke can be turned green by a mixture: solvent yellow 33, solvent green 3, [[lactose]], [[magnesium carbonate]] plus [[sodium carbonate]] added to [[potassium chlorate]].<ref name=firework>
{{cite web
 | title = Firework Chemicals (list)
 | year = 2008
 | website = Sylighter
 | url=http://www.skylighter.com/mall/chemicals.asp
 | access-date=11 January 2008
}}
</ref>
{{Clear}}

=== Biology ===
<gallery mode="packed" heights="150px">
Plagiomnium affine laminazellen.jpeg|The chloroplasts of plant cells contain a high concentration of [[chlorophyll]], making them appear green.
Caerulea3 crop.jpg|[[Frog]]s often appear green because [[dermis|dermal]] [[iridophore]]s reflect blue light through a yellow upperlayer, filtering the light to be primarily green.
Yellow-naped Amazon.jpg|A yellow-naped Amazon [[parrot]], colored green for camouflage in the jungle
Micrommata virescens (Arcugnano).jpg|The [[Micrommata virescens|green huntsman spider]] is green due to the presence of [[Bilin (biochemistry)|bilin]] pigments in the spider's [[hemolymph]] and [[Interstitial fluid|tissue fluids]]
</gallery>
Green is common in nature, as many plants are green because of a complex chemical known as chlorophyll, which is involved in [[photosynthesis]]. Chlorophyll absorbs the long wavelengths of light (red) and short wavelengths of light (blue) much more efficiently than the wavelengths that appear green to the human eye, so light reflected by plants is enriched in green.<ref>
{{cite web
 |title = If the Sun's light peaks in the green, why do plants reflect green light?
 |website = Science Line
 |publisher = [[University of California, Santa Barbara|UC Santa Barbara]]
 | date = 2015
 |quote=... why do plants prefer to reflect green light? (giving them their green color) And in particular why do they prefer to absorb red light and with that not efficiently utilizing the sun's radiation?
 |url = http://scienceline.ucsb.edu/getkey.php?key=500
 |access-date = 4 September 2015
}}
</ref>
Chlorophyll absorbs green light poorly because it first arose in organisms living in oceans where purple [[halobacteria]] were already exploiting photosynthesis. Their purple color arose because they extracted energy in the green portion of the spectrum using [[bacteriorhodopsin]]. The new organisms that then later came to dominate the extraction of light were selected to exploit those portions of the spectrum not used by the halobacteria.<ref>
{{cite magazine
 |last=Goldsworthy |first=A.
 |date=10 December 1987
 |title=Why trees are green
 |magazine=[[New Scientist]]
 |volume=116 |issue=1880 |pages=48–52
 |url=https://books.google.com/books?id=vtI9MPk3oVkC&q=why+trees+are+green&pg=PA52
}}
</ref>

[[File:Mamba Dendroaspis angusticeps.jpg|alt=|thumb|A green [[mamba]]]]
Animals typically use the color green as [[camouflage]], blending in with the chlorophyll green of the surrounding environment.<ref name=brit/> Most fish, reptiles, amphibians, and birds appear green because of a [[reflection (physics)|reflection]] of blue light coming through an over-layer of yellow pigment. Perception of color can also be affected by the surrounding environment. For example, broadleaf forests typically have a yellow-green light about them as the trees filter the light. [[Turacoverdin]] is one chemical which can cause a green hue in birds, especially.<ref name=brit/> Invertebrates such as insects or mollusks often display green colors because of [[porphyrin]] pigments, sometimes caused by diet. This can causes their feces to look green as well. Other chemicals which generally contribute to greenness among organisms are [[flavins]] (lychochromes) and hemanovadin.<ref name = brit /> Humans have imitated this by wearing green clothing as a camouflage in military and other fields. Substances that may impart a greenish hue to one's skin include [[biliverdin]], the green pigment in [[bile]], and [[ceruloplasmin]], a [[protein]] that carries copper [[ion]]s in [[chelation]].

The [[Micrommata virescens|green huntsman spider]] is green due to the presence of bilin pigments in the spider's hemolymph (circulatory system fluids) and [[Interstitial fluid|tissue fluids]].<ref>
{{cite journal
 |last1=Oxford    |first1=G.S.
 |last2=Gillespie |first2=R.G.
 |year=1998
 |title=Evolution and ecology of spider coloration
 |journal=[[Annual Review of Entomology]]
 |volume=43  |issue=1  |pages=619–643
 |doi=10.1146/annurev.ento.43.1.619
 |pmid=15012400|s2cid=6963733
}}
</ref>
It hunts insects in green vegetation, where it is well camouflaged.

=== Green eyes ===
{{Main|Eye color#Green}}There is no green pigment in green eyes; like the color of blue eyes, it is an optical illusion; its appearance is caused by the combination of an amber or light brown pigmentation of the [[Stroma of cornea|stroma]], given by a low or moderate concentration of [[melanin]], with the blue tone imparted by the [[Rayleigh scattering]] of the reflected light.<ref>
{{cite book
 |last=Fox |first=Denis Llewellyn
 |year=1979
 |title=Biochromy: Natural coloration of living things
 |publisher=University of California Press
 |isbn=0-520-03699-9
 |page=9
}}
</ref>
Nobody is brought into the world with green eyes. An infant has one of two eye hues: dark or blue. Following birth, cells called melanocytes start to discharge melanin, the earthy colored shade, in the child's irises. This begins happening since melanocytes respond to light in time.<ref>
{{Cite web
 |last=Brolley |first=Brittany
 |date=2019-04-19 |df=dmy-all
 |title=The truth about green eyes
 |website=TheList.com
 |url=https://www.thelist.com/150818/the-truth-about-green-eyes/
 |access-date=2020-08-12 |language=en-US
}}
</ref>
Green eyes are most common in [[Northern Europe|Northern]] and [[Central Europe]].<ref>
{{cite web
 |title=Blue eyes versus brown eyes: A primer on eye color
 |website=Eyedoctorguide.com
 |url=http://www.eyedoctorguide.com/eye_general/eye_color.html
 |access-date=23 December 2011
 |archive-url=https://archive.today/20121208222443/http://www.eyedoctorguide.com/eye_general/eye_color.html
 |archive-date=8 December 2012
}}
</ref><ref>
{{cite web
 |title=Why do Europeans have so many hair and eye colors?
 |website=Cogweb.ucla.edu
 |publisher=[[University of California, Los Angeles|UCLA]]
 |url=http://cogweb.ucla.edu/ep/Frost_06.html
 |access-date=23 December 2011
}}
</ref>
They can also be found in [[Southern Europe]], [[West Asia]], [[Central Asia]], and [[South Asia]].{{Citation needed|date=November 2020}} In [[Iceland]], 89% of women and 87% of men have either blue or green eye color.<ref name=Rafnsson>
{{cite journal
 |vauthors=Rafnsson V, Hrafnkelsson J, Tulinius H, Sigurgeirsson B, Olafsson JH
 |year=2004
 |title=Risk factors for malignant melanoma in an Icelandic population sample
 |journal=Prev Med
 |volume=39 |issue=2 |pages=247–52
 |pmid=15226032 |doi=10.1016/j.ypmed.2004.03.027
}}
</ref>
A study of Icelandic and Dutch adults found green eyes to be much more prevalent in women than in men.<ref>
{{cite journal
 |first1=Patrick  |last1=Sulem       |first2=Daniel F.   |last2=Gudbjartsson
 |first3=Simon N. |last3= Stacey     |first4=Agnar       |last4=Helgason
 |first5= Thorunn |last5=Rafnar      |first6=Kristinn P. |last6=Magnusson
 |display-authors=etal
 |date=December 2007
 |title=Genetic determinants of hair, eye, and skin pigmentation in Europeans
 |journal=Nature Genetics
 |volume=39  |issue=12 |pages=1443–1452
 |doi=10.1038/ng.2007.13
 |pmid=17952075 |s2cid=19313549 |url=https://uni.hi.is/apalsson/files/2011/10/PM_NG07.pdf
 |via=Anar Palsson / Háskóli Íslands ([[University of Iceland]] – uni.hi.is)
 |access-date=7 August 2012
}}
</ref>