@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/