TY  - JOUR
AU  - A. Lelek
AU  - Jan Mycielski
TI  - Some conditions for a mapping to be a covering
JO  - Fundamenta Mathematicae
PY  - 1960
SP  - 295
EP  - 300
VL  - 49
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/fm-49-3-295-300/
DO  - 10.4064/fm-49-3-295-300
LA  - en
ID  - 10_4064_fm_49_3_295_300
ER  -