@book(Barendregt84,
 author       = "Henk Barendregt",
 year         = "1984",
 title        = "{The Lambda Calculus: Its Syntax and Semantics}",
 series       = "Studies in Logic and the Foundations of Mathematics",
 volume       = "103",
 publisher    = "North-Holland",
)
@incollection(bekic1984,
 author       = "Hans Beki\'{c}",
 year         = "1984",
 title        = "Definable operations in general algebras, and the theory of automata and flowcharts",
 editor       = "C.B. Jones",
 booktitle    = "Programming Languages and Their Definition",
 series       = "Lecture Notes in Computer Science",
 volume       = "177",
 publisher    = "Springer Berlin Heidelberg",
 pages        = "30--55",
 doi          = "10.1007/BFb0048939",
)
@article(cou86,
 author       = "Bruno Courcelle",
 year         = "1986",
 title        = "Equivalences and Transformations of Regular Systems -- Applications to Recursive Program Schemes and Grammars",
 journal      = "Theoretical Computer Science",
 volume       = "42",
 pages        = "1--122",
 doi          = "10.1016/0304-3975(86)90050-2",
)
@unpublished(esik2007modern,
 author       = "Zolt{\'a}n {\'E}sik and Werner Kuich",
 year         = "2007",
 title        = "Modern automata theory",
 note         = "Unpublished manuscript",
)
@inproceedings(esle2002,
 author       = "Zolt{\'a}n {\'E}sik and Hans Lei{\ss }",
 year         = "2002",
 title        = "Greibach Normal Form in Algebraically Complete Semirings",
 booktitle    = "CSL '02: Proceedings of the 16th International Workshop and 11th Annual Conference of the EACSL on Computer Science Logic",
 publisher    = "Springer-Verlag",
 address      = "London, UK",
 pages        = "135--150",
 doi          = "10.1007/3-540-45793-3\_10",
)
@article(EsikLeiss05,
 author       = "Zolt{\'a}n {\'E}sik and Hans Lei{\ss }",
 year         = "2005",
 title        = "Algebraically Complete Semirings and {G}reibach Normal Form",
 journal      = "Annals of Pure and Applied Logic",
 volume       = "133",
 pages        = "173--203",
 doi          = "10.1016/j.apal.2004.10.008",
)
@article(Gruska71,
 author       = "Jozef Gruska",
 year         = "1971",
 title        = "A characterization of context-free languages",
 journal      = "J. Comput. Syst. Sci.",
 volume       = "5",
 number       = "4",
 pages        = "353--364",
 doi          = "10.1016/S0022-0000(71)80023-5",
)
@inproceedings(Hopkins08a,
 author       = "Mark Hopkins",
 year         = "2008",
 title        = "The Algebraic Approach {I}: The Algebraization of the {C}homsky Hierarchy",
 editor       = "R. Berghammer and B. M{\"o}ller and G. Struth",
 booktitle    = "Proc. 10th Int. Conf. Relational Methods in Computer Science and 5th Int. Conf. Applications of Kleene Algebra (RelMiCS/AKA 2008)",
 series       = "Lecture Notes in Computer Science",
 volume       = "4988",
 publisher    = "Springer-Verlag",
 address      = "Berlin Heidelberg",
 pages        = "155--172",
 doi          = "10.1007/978-3-540-78913-0\_13",
)
@inproceedings(Hopkins08b,
 author       = "Mark Hopkins",
 year         = "2008",
 title        = "The Algebraic Approach {II}: Dioids, Quantales and Monads",
 editor       = "R. Berghammer and B. M{\"o}ller and G. Struth",
 booktitle    = "Proc. 10th Int. Conf. Relational Methods in Computer Science and 5th Int. Conf. Applications of Kleene Algebra (RelMiCS/AKA 2008)",
 series       = "Lecture Notes in Computer Science",
 volume       = "4988",
 publisher    = "Springer-Verlag",
 address      = "Berlin Heidelberg",
 pages        = "173--190",
 doi          = "10.1007/978-3-540-78913-0\_14",
)
@inproceedings(kozen81,
 author       = "Dexter Kozen",
 year         = "1981",
 title        = "On Induction vs. *-Continuity",
 booktitle    = "Proc. Logics of Programs",
 series       = "Lecture Notes in Computer Science (LNCS)",
 volume       = "131",
 publisher    = "Springer",
 pages        = "167--176",
 doi          = "10.1007/BFb0025769",
)
@article(kozen83,
 author       = "Dexter Kozen",
 year         = "1983",
 title        = "Results on the propositional [mu]-calculus",
 journal      = "Theoretical Computer Science",
 volume       = "27",
 number       = "3",
 pages        = "333 -- 354",
 doi          = "10.1016/0304-3975(82)90125-6",
)
@book(K91a,
 author       = "Dexter Kozen",
 year         = "1991",
 title        = "The Design and Analysis of Algorithms",
 publisher    = "Springer-Verlag",
 address      = "New York",
 doi          = "10.1007/978-1-4612-4400-4",
)
@inproceedings(leiss92b,
 author       = "Hans Lei{\ss }",
 year         = "1992",
 title        = "Towards {Kleene} Algebra with Recursion",
 booktitle    = "CSL '91: Proceedings of the 5th Workshop on Computer Science Logic",
 publisher    = "Springer-Verlag",
 address      = "London, UK",
 pages        = "242--256",
 doi          = "10.1007/BFb0023771",
)
@book(Winskel93,
 author       = "Glynn Winskel",
 year         = "1993",
 title        = "The Formal Semantics of Programming Languages",
 publisher    = "MIT Press",
)