@article{05029609,
title = {Regular homotopy and total curvature I: Circle immersions into surfaces.},
journal = {Geometry \& Topology},
volume = {6},
year = {2006},
pages = {459-492},
doi = {10.2140/agt.2006.6.459},
zbl = {1113.53041},
language = {en},
url = {http://dml.mathdoc.fr/item/05029609}
}
Ekholm, Tobias. Regular homotopy and total curvature I: Circle immersions into surfaces.. Geometry & Topology, Tome 6 (2006) pp. 459-492. doi : 10.2140/agt.2006.6.459. http://gdmltest.u-ga.fr/item/05029609/