TY  - JOUR
AU  - Morgado, José
TI  - A characterization of the closure operators by means of one axiom
JO  - Portugaliae mathematica
PY  - 1962
SP  - 155
EP  - 156
VL  - 21
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/PORMA_1962__21_3_114888/
LA  - en
ID  - PORMA_1962__21_3_114888
ER  -