1. Winding quotients and some variants of Fermat's last theorem;Darmon;J. Reine Angew. Math.,1997
2. Algebraic and Automata-Theoretic Properties of Formal Languages;Ginsburg,1975
3. Intersection-closed full AFL and the recursively enumerable languages;Ginsburg;Inf. Control,1973
4. Abstract families of languages generated by bounded languages;Goldstine,1970
5. The hardest context-free language;Greibach;SIAM J. Comput.,1973