Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MAN_1972__196_162255, author = {D.B.J. Chillingworth}, title = {Winding {Numbers} on {Surfaces,} {I.}}, journal = {Mathematische Annalen}, pages = {218--249}, publisher = {mathdoc}, volume = {196}, year = {1972}, zbl = {0221.57001}, url = {http://geodesic.mathdoc.fr/item/MAN_1972__196_162255/} }
D.B.J. Chillingworth. Winding Numbers on Surfaces, I.. Mathematische Annalen, Tome 196 (1972), pp. 218-249. http://geodesic.mathdoc.fr/item/MAN_1972__196_162255/