1. T.M. Apostol, Calculus, 2nd edn. One-Variable Calculus, With an Introduction to Linear Algebra, vol. 1 (Blaisdell, Waltham, MA, 1967), p. 143
2. B. Bolzano, Rein analytischer Beweis des Lehrsatzes dass zwischen je zwey Werthen, die ein entgegengesetztes Resultat gewaehren, wenigstens eine reele Wurzel der Gleichung liege. Prague, 1817. English translation in Russ, S. B. A Translation of Bolzano’s Paper on the Intermediate Value Theorem. Hist. Math. 7, 156–185 (1980)
3. P.A.N. Bosman, E.D. de Jong, Learning probabilistic tree grammars for genetic programming, in Proceedings of 8th International Conference, Parallel Problem Solving from Nature - PPSN VIII, Birmingham, UK, September 18-22, 2004, pp. 192–201. https://doi.org/10.1007/978-3-540-30217-9_20
4. Z. Chi, Statistical properties of context-free grammars. Comput. Linguist. 25(1), 131–160 (1999)
5. N. Chomsky, Three models for the description of language. IRE Trans. Inform. Theory (2), 113–124 (1956). https://doi.org/10.1109/TIT.1956.1056813