60 @article{campeanu2003formal,

    61   title={A formal study of practical regular expressions},

    62   author={C{\^a}mpeanu, Cezar and Salomaa, Kai and Yu, Sheng},

    63   journal={International Journal of Foundations of Computer Science},

    64   volume={14},

    65   number={06},

    66   pages={1007--1018},

    67   year={2003},

    68   publisher={World Scientific}

    69 }

    70 

    71 @article{alfred2014algorithms,

    72   title={Algorithms for finding patterns in strings},

    73   author={Alfred, V},

    74   journal={Algorithms and Complexity},

    75   volume={1},

    76   pages={255},

    77   year={2014},

    78   publisher={Elsevier}

    79 }

    80 

    81 

    82 @article{CAMPEANU2009Intersect,

    83 title = {On the intersection of regex languages with regular languages},

    84 journal = {Theoretical Computer Science},

    85 volume = {410},

    86 number = {24},

    87 pages = {2336-2344},

    88 year = {2009},

    89 note = {Formal Languages and Applications: A Collection of Papers in Honor of Sheng Yu},

    90 issn = {0304-3975},

    91 doi = {https://doi.org/10.1016/j.tcs.2009.02.022},

    92 url = {https://www.sciencedirect.com/science/article/pii/S0304397509001789},

    93 author = {Cezar Câmpeanu and Nicolae Santean},

    94 keywords = {Extended regular expression, Regex automata system, Regex},

    95 abstract = {In this paper we revisit the semantics of extended regular expressions (regex), defined succinctly in the 90s [A.V. Aho, Algorithms for finding patterns in strings, in: Jan van Leeuwen (Ed.), Handbook of Theoretical Computer Science, in: Algorithms and Complexity, vol. A, Elsevier and MIT Press, 1990, pp. 255–300] and rigorously in 2003 by Câmpeanu, Salomaa and Yu [C. Câmpeanu, K. Salomaa, S. Yu, A formal study of practical regular expressions, IJFCS 14 (6) (2003) 1007–1018], when the authors reported an open problem, namely whether regex languages are closed under the intersection with regular languages. We give a positive answer; and for doing so, we propose a new class of machines — regex automata systems (RAS) — which are equivalent to regex. Among others, these machines provide a consistent and convenient method of implementing regex in practice. We also prove, as a consequence of this closure property, that several languages, such as the mirror language, the language of palindromes, and the language of balanced words are not regex languages.}

    96 }

    97 

   118 @misc{KuklewiczHaskell,

   119 	title = {Regex Posix},

   120 	author = {Kuklewicz},

   121 	keywords = {Buggy C POSIX Lexing Libraries},

   122 	url = {https://wiki.haskell.org/Regex_Posix},

   123 	year = {2017}

   124 }

   125 

   126 

   127 @techreport{grathwohl2014crash,

   128   title={A Crash-Course in Regular Expression Parsing and Regular Expressions as Types},

   129   author={Grathwohl, Niels Bj{\o}rn Bugge and Henglein, Fritz and Rasmussen, Ulrik Terp},

   130   year={2014},

   131   institution={Technical report, University of Copenhagen}

   132 }

   133