@article(Alberucci_Facchini2009:transitive_reflexive,
 author       = {L. Alberucci and A. Facchini},
 year         = {2009},
 title        = {The modal $\mu$-calculus over restricted classes of transition systems},
 journal      = {Journal of Symbolic Logic},
 volume       = {74},
 number       = {4},
 pages        = {1367--1400},
 doi          = {10.2178/jsl/1254748696},
)
@techreport(AndersenPMC:1994,
 author       = {H. R. Andersen},
 year         = {1994},
 title        = {A Polyadic Modal {$\mu$}-Calculus},
 type         = {Technical Report},
 number       = {ID-TR: 1994-195},
 institution  = {Dept.\ of Computer Science, Technical University of Denmark, Copenhagen},
 doi          = {10.1.1.42.1859},
)
@article(RAIRO:arnold99,
 author       = {A. Arnold},
 year         = {1999},
 title        = {The modal $\mu$-calculus alternation hierarchy is strict on binary trees},
 journal      = {RAIRO - Theoretical Informatics and Applications},
 volume       = {33},
 pages        = {329--339},
 doi          = {10.1051/ita:1999121},
)
@incollection(BraStir01,
 author       = {J. Bradfield and C. Stirling},
 year         = {2001},
 title        = {Modal logics and $\mu$-calculi: an introduction},
 editor       = {J. Bergstra and A. Ponse and S. Smolka},
 booktitle    = {{H}andbook of {P}rocess {A}lgebra},
 publisher    = {Elsevier},
 pages        = {293--330},
 doi          = {10.1016/B978-044482830-9/50022-9},
)
@incollection(BraStir04,
 author       = {J. Bradfield and C. Stirling},
 year         = {2007},
 title        = {Modal mu-calculi},
 editor       = {P. Blackburn and J. van Benthem and F. Wolter},
 booktitle    = {{H}andbook of {M}odal {L}ogic: {S}tudies in {L}ogic and {P}ractical {R}easoning {V}olume 3},
 publisher    = {Elsevier},
 pages        = {721--756},
 doi          = {10.1016/S1570-2464(07)80015-2},
)
@inproceedings(CONCUR::Bradfield1996,
 author       = {J. C. Bradfield},
 year         = {1996},
 title        = {The Modal $\mu$-calculus Alternation Hierarchy Is Strict},
 booktitle    = {Proc.\ 7th Conf.\ on Concurrency Theory, {CONCUR'96}},
 series       = {LNCS},
 volume       = {1119},
 publisher    = {Springer},
 pages        = {233--246},
 doi          = {10.1007/3-540-61604-7\_58},
)
@article(bradfield:rairo99,
 author       = {J. C. Bradfield},
 year         = {1999},
 title        = {Fixpoint Alternation: Arithmetic, Transition Systems, and the Binary Tree},
 journal      = {RAIRO - Theoretical Informatics and Applications},
 volume       = {33},
 number       = {4/5},
 pages        = {341--356},
 doi          = {10.1051/ita:1999122},
)
@article(DAgostino_Lenzi2010:transitive,
 author       = {G. D'Agostino and Giacomo Lenzi},
 year         = {2010},
 title        = {On the $\mu$-calculus over transitive and finite transitive frames},
 journal      = {Theoretical Computer Science},
 volume       = {411},
 number       = {50},
 pages        = {4273--4290},
 doi          = {10.1016/j.tcs.2010.09.002},
)
@inproceedings(EL86,
 author       = {E. A. Emerson and C. L. Lei},
 year         = {1986},
 title        = {Efficient Model Checking in Fragments of the Propositional {$\mu$}--Calculus},
 booktitle    = {Symposion on Logic in Computer Science},
 publisher    = {IEEE},
 address      = {Washington, D.C., USA},
 pages        = {267--278},
)
@article(APAL::Grohe1996,
 author       = {M. Grohe},
 year         = {1996},
 title        = {Arity hierarchies},
 journal      = {Annals of Pure and Applied Logic},
 volume       = {82},
 number       = {2},
 pages        = {103--163},
 doi          = {10.1016/0168-0072(95)00072-0},
)
@article(GutierrezKL14,
 author       = {J. Gutierrez and F. Klaedtke and M. Lange},
 year         = {2014},
 title        = {The {$\mu$}-Calculus Alternation Hierarchy Collapses over Structures with Restricted Connectivity},
 journal      = {Theoretical Computer Science},
 volume       = {560},
 number       = {3},
 pages        = {292--306},
 doi          = {10.1016/j.tcs.2014.03.027},
)
@article(Imm:relqcp,
 author       = {N. Immerman},
 year         = {1986},
 title        = {Relational Queries Computable in Polynomial Time},
 journal      = {Information and Control},
 volume       = {68},
 number       = {1--3},
 pages        = {86--104},
 doi          = {10.1016/S0019-9958(86)80029-8},
)
@article(Kna28,
 author       = {B. Knaster},
 year         = {1928},
 title        = {Un th\'eor\`em sur les fonctions d'ensembles},
 journal      = {Annals Soc. Pol. Math},
 volume       = {6},
 pages        = {133--134},
)
@inproceedings(ICALP::Kozen1982,
 author       = {D. Kozen},
 year         = {1982},
 title        = {Results on the Propositional {$\mu$}-Calculus},
 booktitle    = {Proc.\ 9th Int.\ Coll.\ on Automata, Languages and Programming, {ICALP'82}},
 series       = {LNCS},
 volume       = {140},
 publisher    = {Springer},
 pages        = {348--359},
 doi          = {10.1007/BFb0012782},
)
@inproceedings(LL-FICS12,
 author       = {M. Lange and E. Lozes},
 year         = {2012},
 title        = {Model Checking the Higher-Dimensional Modal $\mu$-Calculus},
 booktitle    = {Proc.\ 8th Workshop on Fixpoints in Computer Science, {FICS'12}},
 series       = {Electr.\ Proc.\ in Theor.\ Comp.\ Sc.},
 volume       = {77},
 pages        = {39--46},
 doi          = {10.4204/EPTCS.77},
)
@article(LLVG:TCS:2014,
 author       = {M. Lange and E. Lozes and M. Vargas Guzm{\'a}n},
 year         = {2014},
 title        = {Model-Checking Process Equivalences},
 journal      = {Theoretical Computer Science},
 volume       = {560},
 pages        = {326--347},
 doi          = {10.1016/j.tcs.2014.08.020},
)
@inproceedings(ICALP::Lenzi1996,
 author       = {G. Lenzi},
 year         = {1996},
 title        = {A Hierarchy Theorem for the {$\mu$}-Calculus},
 booktitle    = {Proc.\ 23rd Int.\ Coll.\ on Automata, Languages and Programming, {ICALP'96}},
 series       = {LNCS},
 volume       = {1099},
 publisher    = {Springer},
 pages        = {87--97},
 doi          = {10.1007/3-540-61440-0\_119},
)
@inproceedings(LICS::Niwinski1988,
 author       = {D. Niwi{\'n}ski},
 year         = {1988},
 title        = {Fixed Points vs.\ Infinite Generation},
 booktitle    = {Proc.\ 3rd Ann.\ Symp.\ on Logic in Computer Science, {LICS'88}},
 organization = {IEEE Computer Society},
 pages        = {402--409},
)
@article(Otto/99b,
 author       = {M. Otto},
 year         = {1999},
 title        = {Bisimulation-invariant {PTIME} and higher-dimensional $\mu$-calculus},
 journal      = {Theor.~Comput.~Sci.},
 volume       = {224},
 number       = {1--2},
 pages        = {237--265},
 doi          = {10.1016/S0304-3975(98)00314-4},
)
@inproceedings(Stirling95,
 author       = {C. Stirling},
 year         = {1995},
 title        = {Local Model Checking Games},
 booktitle    = {Proc.\ 6th Conf.\ on Concurrency Theory, {CONCUR}'95},
 series       = {LNCS},
 volume       = {962},
 publisher    = {Springer},
 pages        = {1--11},
 doi          = {10.1007/3-540-60218-6\_1},
)
@inproceedings(1996:tacas:stirling,
 author       = {C. Stirling},
 year         = {1996},
 title        = {Games and Modal $\mu$-Calculus},
 editor       = {T. Margaria and B. Steffen},
 booktitle    = {Proc.\ 2nd Int. Workshop on Tools and Algorithms for the Construction and Analysis of Systems, {TACAS'96}},
 series       = {LNCS},
 volume       = {1055},
 publisher    = {Springer},
 pages        = {298--312},
 doi          = {10.1007/3-540-61042-1\_51},
)
@article(Tars55,
 author       = {A. Tarski},
 year         = {1955},
 title        = {A Lattice-theoretical Fixpoint Theorem and its Application},
 journal      = {Pacific Journal of Mathematics},
 volume       = {5},
 pages        = {285--309},
 doi          = {10.2140/pjm.1955.5.285},
)
@inproceedings(STOC::Vardi1982,
 author       = {M. Y. Vardi},
 year         = {1982},
 title        = {The Complexity of Relational Query Languages (Extended Abstract)},
 booktitle    = {Proc.\ 14th Symp.\ on Theory of Computing, {STOC'82}},
 publisher    = {ACM},
 address      = {San Francisco, CA, USA},
 pages        = {137--146},
 doi          = {10.1145/800070},
)
@article(journals/tcs/Walukiewicz02,
 author       = {I. Walukiewicz},
 year         = {2002},
 title        = {Monadic second-order logic on tree-like structures},
 journal      = {Theor. Comput. Sci},
 volume       = {275},
 number       = {1-2},
 pages        = {311--346},
 doi          = {10.1016/S0304-3975(01)00185-2},
)