TY  - JOUR
AU  - Button, Robert Warren
TI  - A Non-Standard Characterization of Perfect Mappings
JO  - Canadian journal of mathematics
PY  - 1976
SP  - 1277
EP  - 1279
VL  - 28
IS  - 6
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1976-126-2/
DO  - 10.4153/CJM-1976-126-2
ID  - 10_4153_CJM_1976_126_2
ER  -