@article{1102702809, author = {Wente, Henry C.}, title = {Counterexample to a conjecture of H. Hopf.}, journal = {Pacific J. Math.}, volume = {125}, number = {2}, year = {1986}, pages = { 193-243}, language = {en}, url = {http://dml.mathdoc.fr/item/1102702809} }
Wente, Henry C. Counterexample to a conjecture of H. Hopf.. Pacific J. Math., Tome 125 (1986) no. 2, pp. 193-243. http://gdmltest.u-ga.fr/item/1102702809/