TY  - JOUR
AU  - Timo Lepistö
TI  - An extension for the concept of finite index of a context-free grammar
JO  - Annales Fennici Mathematici
PY  - 1972
VL  - 501-520
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1972.518/
DO  - 10.5186/aasfm.1972.518
LA  - en
ID  - AFM_1972_501-520_a2
ER  -