@article{05875574,
title = {On the developable ruled surfaces of low smoothness.},
journal = {Sibirskij Matematicheskij Zhurnal},
volume = {50},
year = {2009},
pages = {1163-1175},
zbl = {1224.53010},
language = {en},
url = {http://dml.mathdoc.fr/item/05875574}
}
Sabitov, I.Kh. On the developable ruled surfaces of low smoothness.. Sibirskij Matematicheskij Zhurnal, Tome 50 (2009) pp. 1163-1175. http://gdmltest.u-ga.fr/item/05875574/