TY  - JOUR
AU  - Pondělíček, Bedřich
TI  - A Relation for Closure Operations on a Semigroup
JO  - Mathematica slovaca
PY  - 1973
SP  - 249
EP  - 256
VL  - 23
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MASLO_1973__23_3_a7/
LA  - en
ID  - MASLO_1973__23_3_a7
ER  -