@book{7124,
	author = {Pogorelov, A. V.},
	title = {Differential geometry./},
	publisher = {P. Noordhoff},
	year = {[1967]},
	address = {Groningen,},
	note = {Translation of Lekt︠s︡ii po different︠s︡ialʹnoĭ geometrii.}
}