@article{GDZPPN002306859,
title = {Winding Numbers on Surfaces II. Applications.},
journal = {Mathematische Annalen},
volume = {196},
year = {1972},
pages = {131-154},
zbl = {0231.57002},
url = {http://dml.mathdoc.fr/item/GDZPPN002306859}
}
Chillingworth, D.R.J. Winding Numbers on Surfaces II. Applications.. Mathematische Annalen, Tome 196 (1972) pp. 131-154. http://gdmltest.u-ga.fr/item/GDZPPN002306859/