Context-free grammar (English Wikipedia)

Analysis of information sources in references of the Wikipedia article "Context-free grammar" in English language version.

Last modified: 03:10:42, 3 August 2026 (UTC)

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Chomsky, Noam (Sep 1956). "Three models for the description of language". IEEE Transactions on Information Theory. 2 (3): 113–124. Bibcode:1956IRTIT...2..113C. doi:10.1109/TIT.1956.1056813. S2CID 19519474.

ams.org (Global: 434^th place; English: 249^th place)

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Nijholt, Anton (1980). Context-free grammars: covers, normal forms, and parsing. Lecture Notes in Computer Science. Vol. 93. Springer. p. 8. ISBN 978-3-540-10245-8. MR 0590047.

archive.org (Global: 6^th place; English: 6^th place)

Hopcroft & Ullman 1979, p. 106. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, pp. 90–92. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 103, Exercise 4.1a. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 103, Exercise 4.1b. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Aho, Alfred Vaino; Lam, Monica S.; Sethi, Ravi; Ullman, Jeffrey David (2007). "4.2.7 Context-Free Grammars Versus Regular Expressions" (print). Compilers: Principles, Techniques, & Tools (2nd ed.). Boston, MA USA: Pearson Addison-Wesley. pp. 205–206. ISBN 9780321486813. Every construct that can be described by a regular expression can be described by a [context-free] grammar, but not vice-versa.
Hopcroft & Ullman 1979, p. 131. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 131-132, Theorem 6.2. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 132-134, Theorem 6.3. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 135-136, Theorem 6.5. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 134-135, Theorem 6.4. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 88, Lemma 4.1. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 89, Lemma 4.2. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 90, Theorem 4.3. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman (1979, p. 214, Exercise 8.10a) The problem remains undecidable even if the language is produced by a "linear" context-free grammar (i.e., with at most one nonterminal in each rule's right-hand side, cf. Exercise 4.20, p. 105). Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, p. 137-138, Theorem 6.6. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Sipser 1997, p. 181, Theorem 5.10. Sipser, Michael (1997). Introduction to the Theory of Computation (1st ed.). PWS Publishing. ISBN 978-0-534-94728-6. (accessible to patrons with print disabilities) Chapter 2: Context-Free Grammars, pp. 91–122; Section 4.1.2: Decidable problems concerning context-free languages, pp. 156–159; Section 5.1.1: Reductions via computation histories: pp. 176–183.
Hopcroft & Ullman 1979, p. 281. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
Hopcroft & Ullman 1979, pp. 200–201, Theorem 8.9. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
The notation here is that of Sipser (1997, p. 94). Hopcroft & Ullman (1979, p. 79) define context-free grammars as 4-tuples in the same way, but with different variable names. Sipser, Michael (1997). Introduction to the Theory of Computation (1st ed.). PWS Publishing. ISBN 978-0-534-94728-6. (accessible to patrons with print disabilities) Chapter 2: Context-Free Grammars, pp. 91–122; Section 4.1.2: Decidable problems concerning context-free languages, pp. 156–159; Section 5.1.1: Reductions via computation histories: pp. 176–183. Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.
This is a consequence of the unit-production elimination theorem in Hopcroft & Ullman (1979, p. 91, Theorem 4.4) Hopcroft, John E.; Ullman, Jeffrey D. (1979). Introduction to Automata Theory, Languages, and Computation (1st ed.). Addison-Wesley. ISBN 0-201-02988-X. (accessible to patrons with print disabilities) Chapter 4: Context-Free Grammars, pp. 77–106; Chapter 6: Properties of Context-Free Languages, pp. 125–137.

arxiv.org (Global: 49^th place; English: 31^st place)

Lillian Lee (2002). "Fast Context-Free Grammar Parsing Requires Fast Boolean Matrix Multiplication" (PDF). J ACM. 49 (1): 1–15. arXiv:cs/0112018. doi:10.1145/505241.505242. S2CID 1243491. Archived (PDF) from the original on 2003-04-27.

books.google.com (Global: 3^rd place; English: 3^rd place)

Hazewinkel, Michiel (1994). Encyclopaedia of mathematics: an updated and annotated translation of the Soviet "Mathematical Encyclopaedia". Springer. Vol. IV, p. 56. ISBN 978-1-55608-003-6..

cmu.edu (Global: 2,125^th place; English: 1,347^th place)

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Leslie Valiant (Jan 1974). General context-free recognition in less than cubic time (Technical report). Carnegie Mellon University. p. 11.

cornell.edu (Global: 308^th place; English: 253^rd place)

cs.cornell.edu

Lillian Lee (2002). "Fast Context-Free Grammar Parsing Requires Fast Boolean Matrix Multiplication" (PDF). J ACM. 49 (1): 1–15. arXiv:cs/0112018. doi:10.1145/505241.505242. S2CID 1243491. Archived (PDF) from the original on 2003-04-27.

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doi.org

Chomsky, Noam (Sep 1956). "Three models for the description of language". IEEE Transactions on Information Theory. 2 (3): 113–124. Bibcode:1956IRTIT...2..113C. doi:10.1109/TIT.1956.1056813. S2CID 19519474.
Leslie G. Valiant (1975). "General context-free recognition in less than cubic time". Journal of Computer and System Sciences. 10 (2): 308–315. doi:10.1016/s0022-0000(75)80046-8.
Lillian Lee (2002). "Fast Context-Free Grammar Parsing Requires Fast Boolean Matrix Multiplication" (PDF). J ACM. 49 (1): 1–15. arXiv:cs/0112018. doi:10.1145/505241.505242. S2CID 1243491. Archived (PDF) from the original on 2003-04-27.
D.J. Rosenkrantz and R.E. Stearns (1970). "Properties of Deterministic Top Down Grammars". Information and Control. 17 (3): 226–256. doi:10.1016/S0019-9958(70)90446-8.
Ogden, William (September 1968). "A helpful result for proving inherent ambiguity". Mathematical Systems Theory. 2 (3): 191–194. doi:10.1007/bf01694004. ISSN 0025-5661. S2CID 13197551. Here: p.4
Shieber, Stuart (1985). "Evidence against the context-freeness of natural language" (PDF). Linguistics and Philosophy. 8 (3): 333–343. doi:10.1007/BF00630917. S2CID 222277837. Archived (PDF) from the original on 2004-04-15..
Pullum, Geoffrey K.; Gerald Gazdar (1982). "Natural languages and context-free languages". Linguistics and Philosophy. 4 (4): 471–504. doi:10.1007/BF00360802. S2CID 189881482..
Culy, Christopher (1985). "The Complexity of the Vocabulary of Bambara". Linguistics and Philosophy. 8 (3): 345–351. doi:10.1007/BF00630918. S2CID 189881984..

dx.doi.org

Ogden, William (September 1968). "A helpful result for proving inherent ambiguity". Mathematical Systems Theory. 2 (3): 191–194. doi:10.1007/bf01694004. ISSN 0025-5661. S2CID 13197551. Here: p.4

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Shieber, Stuart (1985). "Evidence against the context-freeness of natural language" (PDF). Linguistics and Philosophy. 8 (3): 333–343. doi:10.1007/BF00630917. S2CID 222277837. Archived (PDF) from the original on 2004-04-15..

mun.ca (Global: 5,616^th place; English: 3,068^th place)

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Norvell, Theodore. "A Short Introduction to Regular Expressions and Context-Free Grammars" (PDF). p. 4. Archived (PDF) from the original on 2005-03-24. Retrieved August 24, 2012.

pearson.com (Global: low place; English: low place)

Aho, Alfred Vaino; Lam, Monica S.; Sethi, Ravi; Ullman, Jeffrey David (2007). "4.2.7 Context-Free Grammars Versus Regular Expressions" (print). Compilers: Principles, Techniques, & Tools (2nd ed.). Boston, MA USA: Pearson Addison-Wesley. pp. 205–206. ISBN 9780321486813. Every construct that can be described by a regular expression can be described by a [context-free] grammar, but not vice-versa.

psu.edu (Global: 299^th place; English: 159^th place)

citeseerx.ist.psu.edu

Aiken, A.; Murphy, B. (1991). "Implementing Regular Tree Expressions". ACM Conference on Functional Programming Languages and Computer Architecture. pp. 427–447. CiteSeerX 10.1.1.39.3766. {{cite conference}}: Cite uses deprecated parameter |citeseerx= (help); Sect.4

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Chomsky, Noam (Sep 1956). "Three models for the description of language". IEEE Transactions on Information Theory. 2 (3): 113–124. Bibcode:1956IRTIT...2..113C. doi:10.1109/TIT.1956.1056813. S2CID 19519474.
Lillian Lee (2002). "Fast Context-Free Grammar Parsing Requires Fast Boolean Matrix Multiplication" (PDF). J ACM. 49 (1): 1–15. arXiv:cs/0112018. doi:10.1145/505241.505242. S2CID 1243491. Archived (PDF) from the original on 2003-04-27.
Ogden, William (September 1968). "A helpful result for proving inherent ambiguity". Mathematical Systems Theory. 2 (3): 191–194. doi:10.1007/bf01694004. ISSN 0025-5661. S2CID 13197551. Here: p.4
Shieber, Stuart (1985). "Evidence against the context-freeness of natural language" (PDF). Linguistics and Philosophy. 8 (3): 333–343. doi:10.1007/BF00630917. S2CID 222277837. Archived (PDF) from the original on 2004-04-15..
Pullum, Geoffrey K.; Gerald Gazdar (1982). "Natural languages and context-free languages". Linguistics and Philosophy. 4 (4): 471–504. doi:10.1007/BF00360802. S2CID 189881482..
Culy, Christopher (1985). "The Complexity of the Vocabulary of Bambara". Linguistics and Philosophy. 8 (3): 345–351. doi:10.1007/BF00630918. S2CID 189881984..

softwarepreservation.org (Global: low place; English: low place)

Backus, J. W. (1959). "The syntax and semantics of the proposed international algebraic language of the Zurich ACM-GAMM Conference". Proceedings of the International Conference on Information Processing. UNESCO. pp. 125–132.

stanford.edu (Global: 194^th place; English: 182^nd place)

web.stanford.edu

Jurafsky, Daniel; Martin, James H. (29 December 2021). "Constituency Grammars" (PDF). Stanford University. Archived (PDF) from the original on 2017-03-14. Retrieved 28 October 2022.

web.archive.org (Global: 1^st place; English: 1^st place)

Jurafsky, Daniel; Martin, James H. (29 December 2021). "Constituency Grammars" (PDF). Stanford University. Archived (PDF) from the original on 2017-03-14. Retrieved 28 October 2022.
Lillian Lee (2002). "Fast Context-Free Grammar Parsing Requires Fast Boolean Matrix Multiplication" (PDF). J ACM. 49 (1): 1–15. arXiv:cs/0112018. doi:10.1145/505241.505242. S2CID 1243491. Archived (PDF) from the original on 2003-04-27.
Norvell, Theodore. "A Short Introduction to Regular Expressions and Context-Free Grammars" (PDF). p. 4. Archived (PDF) from the original on 2005-03-24. Retrieved August 24, 2012.
Shieber, Stuart (1985). "Evidence against the context-freeness of natural language" (PDF). Linguistics and Philosophy. 8 (3): 333–343. doi:10.1007/BF00630917. S2CID 222277837. Archived (PDF) from the original on 2004-04-15..

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Ogden, William (September 1968). "A helpful result for proving inherent ambiguity". Mathematical Systems Theory. 2 (3): 191–194. doi:10.1007/bf01694004. ISSN 0025-5661. S2CID 13197551. Here: p.4

Context-free grammar (English Wikipedia)

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