TY  - JOUR
AU  - Nadler, Sam B. jr.
TI  - Coverings by closed sets
JO  - Portugaliae mathematica
PY  - 1967
SP  - 51
EP  - 61
VL  - 26
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/PORMA_1967__26_1_115001/
LA  - en
ID  - PORMA_1967__26_1_115001
ER  -