TY  - JOUR
AU  - Frolík, Zdeněk
TI  - Invariance of $G_\delta$-spaces under mappings
JO  - Czechoslovak Mathematical Journal
PY  - 1961
SP  - 258
EP  - 261
VL  - 11
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1961.100459/
DO  - 10.21136/CMJ.1961.100459
LA  - en
ID  - 10_21136_CMJ_1961_100459
ER  -