TY  - JOUR
AU  - Robert Gulliver
TI  - Branched Immersions of Surfaces and Reduction of Topological Type, I.
JO  - Mathematische Zeitschrift
PY  - 1975
SP  - 267
EP  - 288
VL  - 145
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZ_1975__145_172290/
ID  - MZ_1975__145_172290
ER  -