References

1. Hopcroft, J. E., Motwani, R., & Ullman, J. D. (2006). Introduction to Automata Theory, Languages, and Computation (3rd ed.). Pearson Education.

2. Sipser, M. (2012). Introduction to the Theory of Computation (3rd ed.). Cengage Learning.

3. Aho, A. V., Lam, M. S., Sethi, R., & Ullman, J. D. (2006). Compilers: Principles, Techniques, and Tools (2nd ed.). Pearson Education.

4. Chomsky, N. (1956). Three models for the description of language. IRE Transactions on Information Theory, 2(3), 113-124.

5. Knuth, D. E. (1965). On the translation of languages from left to right. Information and Control, 8(6), 607-639.

6. Earley, J. (1970). An efficient context-free parsing algorithm. Communications of the ACM, 13(2), 94-102.

7. Kozen, D. C. (1997). Automata and Computability. Springer.

8. Wikipedia. Context-free grammar. Retrieved from https://en.wikipedia.org/wiki/Context-free_grammar

9. Wikipedia. Ambiguous grammar. Retrieved from https://en.wikipedia.org/wiki/Ambiguous_grammar