@book{82021,
	author = {Darboux, Gaston},
	title = {Lecons sur la Theorie Generale des Surfaces et les Applications Geometriques du Calcul Infinitesimal; part 1 - 4},
	publisher = {Chelsea Publishing Company},
	year = {1972},
	series = {American mathematical society},
	address = {New York}
}