@article{GDZPPN002088452, title = {Minimal Total Absolute Curvature for Immersions}, journal = {Inventiones mathematicae}, volume = {11}, year = {1970}, pages = {209-238}, zbl = {0195.51102}, url = {http://dml.mathdoc.fr/item/GDZPPN002088452} }
KUIPER, N.H. Minimal Total Absolute Curvature for Immersions. Inventiones mathematicae, Tome 11 (1970) pp. 209-238. http://gdmltest.u-ga.fr/item/GDZPPN002088452/