TY  - JOUR
AU  - Čulík, Karel
TI  - On some transformations in context-free grammars and languages
JO  - Czechoslovak Mathematical Journal
PY  - 1967
SP  - 278
EP  - 311
VL  - 17
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1967.100776/
DO  - 10.21136/CMJ.1967.100776
LA  - en
ID  - 10_21136_CMJ_1967_100776
ER  -