Editing Star height problem (section)

==References==
* {{cite book |author-link=Janusz Brzozowski (computer scientist) |first=Janusz A. |last=Brzozowski |chapter=Open problems about regular languages |editor-first=Ronald V. |editor-last=Book |title=Formal language theory—Perspectives and open problems |pages=[https://archive.org/details/formallanguageth0000unse/page/23 23–47] |publisher=Academic Press |location=New York |year=1980 |isbn=978-0-12-115350-2 |chapter-url=https://archive.org/details/formallanguageth0000unse/page/23 }} [https://www.cs.uwaterloo.ca/research/tr/1980/CS-80-03.pdf (technical report version)]
* {{cite book|last1=Colcombet|first1=Thomas|last2=Löding|first2=Christof|title=Computer Science Logic |chapter=The Nesting-Depth of Disjunctive μ-Calculus for Tree Languages and the Limitedness Problem |series=Lecture Notes in Computer Science|volume=5213|year=2008|pages=416–430|issn=0302-9743|doi=10.1007/978-3-540-87531-4_30|isbn=978-3-540-87530-7}}
* {{cite journal |first1=Françoise |last1=Dejean |author-link2=Marcel-Paul Schützenberger |first2=Marcel-Paul |last2=Schützenberger |title=On a Question of Eggan |journal=[[Information and Control]] |volume=9 |issue=1 |pages=23–25 |year=1966 |doi=10.1016/S0019-9958(66)90083-0 |doi-access= }}
* {{cite journal |first=Lawrence C. |last=Eggan |title=Transition graphs and the star-height of regular events | journal=[[Michigan Mathematical Journal]] | volume=10 | issue=4 | pages=385–397 | year=1963 | doi=10.1307/mmj/1028998975 | zbl=0173.01504 | doi-access=free }}
* {{cite journal
 | title = The Loop Complexity of Pure-Group Events
 | year = 1967
 | last = McNaughton |first=Robert
 | journal = Information and Control
 | pages = 167–176
 | volume = 11
 | issue = 1–2
 | doi=10.1016/S0019-9958(67)90481-0
| doi-access = 
 }}
* {{cite book |title=Jewels of Formal Language Theory |last= Salomaa |first= Arto |author-link=Arto Salomaa |year=1981 |publisher=Pitman Publishing |location=Melbourne |isbn=978-0-273-08522-5 |zbl=0487.68063 }}