TY  - JOUR
AU  - Ulrich Hirsch
TI  - On Regular Homotopy of Branched Coverings of the Sphere.
JO  - Manuscripta mathematica
PY  - 1977
SP  - 293
EP  - 306
VL  - 21
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MM2_1977__21_154469/
ID  - MM2_1977__21_154469
ER  -