@article{GDZPPN00231469X,
title = {Branched Immersions of Surfaces and Reduction of Topological Type. II.},
journal = {Mathematische Annalen},
volume = {229},
year = {1977},
pages = {25-48},
zbl = {0338.57014},
url = {http://dml.mathdoc.fr/item/GDZPPN00231469X}
}
Gulliver, Robert. Branched Immersions of Surfaces and Reduction of Topological Type. II.. Mathematische Annalen, Tome 229 (1977) pp. 25-48. http://gdmltest.u-ga.fr/item/GDZPPN00231469X/