TY  - JOUR
AU  - Kasahara, Shouro
TI  - A generalization of a theorem of Polak
JO  - Portugaliae mathematica
PY  - 1967
SP  - 385
EP  - 387
VL  - 26
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/PORMA_1967__26_3_115042/
LA  - en
ID  - PORMA_1967__26_3_115042
ER  -