@article{GDZPPN00231374X, title = {Vector Fields and Chern Numbers.}, journal = {Mathematische Annalen}, volume = {229}, year = {1977}, pages = {263-274}, zbl = {0365.32020}, url = {http://dml.mathdoc.fr/item/GDZPPN00231374X} }
Carrell, J.B.; Liebermann, D.L. Vector Fields and Chern Numbers.. Mathematische Annalen, Tome 229 (1977) pp. 263-274. http://gdmltest.u-ga.fr/item/GDZPPN00231374X/