1. Compilers: Principles Techniques and Tools;Aho,1986
2. M.A. Ahmed, A parsing algorithm for iconic visual programming languages, Master's thesis, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia, December 1996
3. C. Crimi, A. Guerico, G. Nota, G. Pacini, G. Tortora, M. Tucci, Relation grammars for modelling multi-dimensional structures, in: Proceedings of the IEEE Workshop on Visual Languages, IEEE Computer Society Press, Silver spring, MD, 1990, pp. 168–173
4. S. Chang, Ten years of visual languages research, in: Proceedings of the IEEE Symposium on Visual Languages, IEEE Computer Society Press, Silver spring, MD, 1994, pp. 196–205
5. An efficient context-free parsing algorithm;Earley;Communications of the ACM,1970