@article{1256047938, author = {Kauffman, Louis H.}, title = {Planar surface immersions}, journal = {Illinois J. Math.}, volume = {23}, number = {4}, year = {1979}, pages = { 648-665}, language = {en}, url = {http://dml.mathdoc.fr/item/1256047938} }
Kauffman, Louis H. Planar surface immersions. Illinois J. Math., Tome 23 (1979) no. 4, pp. 648-665. http://gdmltest.u-ga.fr/item/1256047938/