@book{24883,
	author = {Akivis, Maks A. and Goldberg, Vladislav V. and Goldberg, Vladislav V;jt. auth},
	title = {Differential geometry of varieties with degenerate gauss maps},
	publisher = {Springer-Verlag},
	year = {2004},
	series = {CMS books in Mathematics },
	address = {New York}
}