TY  - JOUR
AU  - Stefan Czerwik
TI  - Multi-valued contraction mappings in metric spaces. (Short Communication).
JO  - Aequationes mathematicae
PY  - 1977
SP  - 188
EP  - 189
VL  - 16
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/AM2_1977__16_136690/
ID  - AM2_1977__16_136690
ER  -