@article{05029610, title = {Regular homotopy and total curvature. II: Sphere immersions into 3-space.}, journal = {Geometry \& Topology}, volume = {6}, year = {2006}, pages = {493-512}, doi = {10.2140/agt.2006.6.493}, zbl = {1114.53049}, language = {en}, url = {http://dml.mathdoc.fr/item/05029610} }
Ekholm, Tobias. Regular homotopy and total curvature. II: Sphere immersions into 3-space.. Geometry & Topology, Tome 6 (2006) pp. 493-512. doi : 10.2140/agt.2006.6.493. http://gdmltest.u-ga.fr/item/05029610/