TY  - JOUR
AU  - Păun, Gheorghe
TI  - Two infinite hierarchies of languages defined by branching grammars
JO  - Kybernetika
PY  - 1978
SP  - 397
EP  - 407
VL  - 14
IS  - 6
UR  - http://geodesic.mathdoc.fr/item/KYB_1978_14_6_a1/
LA  - en
ID  - KYB_1978_14_6_a1
ER  -