@article{MAN_1972__199_162320,
     author = {D.R.J. Chillingworth},
     title = {Winding {Numbers} on {Surfaces} {II.} {Applications.}},
     journal = {Mathematische Annalen},
     pages = {131--154},
     publisher = {mathdoc},
     volume = {199},
     year = {1972},
     zbl = {0231.57002},
     url = {http://geodesic.mathdoc.fr/item/MAN_1972__199_162320/}
}