TY  - JOUR
AU  - Petrić Milenko
TI  - On some operations on normal digraphs
JO  - Novi Sad Journal of Mathematics
PY  - 1988
SP  - 57
EP  - 67
VL  - 18
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/NSJOM_1988_18_1a_5/
ID  - NSJOM_1988_18_1a_5
ER  -