@article{1077488862, author = {van Kampen, Egbertus R.}, title = {On some characterizations of $2$ -dimensional manifolds}, journal = {Duke Math. J.}, volume = {1}, number = {1}, year = {1935}, pages = { 74-93}, language = {en}, url = {http://dml.mathdoc.fr/item/1077488862} }
van Kampen, Egbertus R. On some characterizations of $2$ -dimensional manifolds. Duke Math. J., Tome 1 (1935) no. 1, pp. 74-93. http://gdmltest.u-ga.fr/item/1077488862/