Editing Age of Earth (section)

==Further reading==
* Baadsgaard, H.; Lerbekmo, J.F.; Wijbrans, J.R., 1993. Multimethod radiometric age for a bentonite near the top of the Baculites reesidei Zone of southwestern Saskatchewan (Campanian-Maastrichtian stage boundary?). ''Canadian Journal of Earth Sciences'', v.30, p.&nbsp;769–775.
* Baadsgaard, H. and Lerbekmo, J.F., 1988. A radiometric age for the Cretaceous-Tertiary boundary based on K-Ar, Rb-Sr, and U-Pb ages of bentonites from Alberta, Saskatchewan, and Montana. ''Canadian Journal of Earth Sciences'', v.25, p.&nbsp;1088–1097.
* Eberth, D.A. and Braman, D., 1990. Stratigraphy, sedimentology, and vertebrate paleontology of the Judith River Formation (Campanian) near Muddy Lake, west-central Saskatchewan. ''Bulletin of Canadian Petroleum Geology'', v.38, no.4, p.&nbsp;387–406.
* Goodwin, M.B. and Deino, A.L., 1989. The first radiometric ages from the Judith River Formation (Upper Cretaceous), Hill County, Montana. ''Canadian Journal of Earth Sciences'', v.26, p.&nbsp;1384–1391.
* Gradstein, F. M.; Agterberg, F.P.; Ogg, J.G.; Hardenbol, J.; van Veen, P.; Thierry, J. and Zehui Huang., 1995. A Triassic, Jurassic and Cretaceous time scale. IN: Bergren, W. A.; Kent, D.V.; Aubry, M-P. and Hardenbol, J. (eds.), ''Geochronology, Time Scales, and Global Stratigraphic Correlation''. Society of Economic Paleontologists and Mineralogists, Special Publication No. 54, p.&nbsp;95–126.
* Harland, W.B., Cox, A.V.; Llewellyn, P.G.; Pickton, C.A.G.; Smith, A.G.; and Walters, R., 1982. ''A Geologic Time Scale'': 1982 edition. Cambridge University Press: Cambridge, 131p.
* Harland, W.B.; [[Richard Lee Armstrong|Armstrong, R.L.]]; Cox, A.V.; Craig, L.E.; Smith, A.G.; Smith, D.G., 1990. ''A Geologic Time Scale'', 1989 edition. Cambridge University Press: Cambridge, p.&nbsp;1–263. {{ISBN|0-521-38765-5}}
* {{cite journal | last1 = Harper | first1 = C.W. Jr | year = 1980 | title = Relative age inference in paleontology | journal = Lethaia | volume = 13 | issue = 3| pages = 239–248 | doi = 10.1111/j.1502-3931.1980.tb00638.x | bibcode = 1980Letha..13..239H }}
* Obradovich, J.D., 1993. A Cretaceous time scale. IN: Caldwell, W.G.E. and Kauffman, E.G. (eds.). ''Evolution of the Western Interior Basin''. Geological Association of Canada, Special Paper 39, p.&nbsp;379–396.
* {{cite journal | last1 = Palmer | first1 = Allison R | year = 1983 | title = The Decade of North American Geology 1983 Geologic Time Scale | journal = Geology | volume = 11 | issue = 9| pages = 503–504 | doi = 10.1130/0091-7613(1983)11<503:tdonag>2.0.co;2 | bibcode = 1983Geo....11..503P }}
* Powell, James Lawrence, 2001, ''Mysteries of Terra Firma: the Age and Evolution of the Earth'', Simon & Schuster, {{ISBN|0-684-87282-X}}