Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{KYB_1972__8_3_a2, author = {Gruska, Jozef}, title = {On the size of context-free grammars}, journal = {Kybernetika}, pages = {--218}, publisher = {mathdoc}, volume = {08}, number = {3}, year = {1972}, mrnumber = {0331877}, zbl = {0241.68037}, language = {en}, url = {http://geodesic.mathdoc.fr/item/KYB_1972__8_3_a2/} }
Gruska, Jozef. On the size of context-free grammars. Kybernetika, Tome 08 (1972) no. 3, p. 218. http://geodesic.mathdoc.fr/item/KYB_1972__8_3_a2/