@book{99948,
	author = {Pontri︠a︡gin, L. S.},
	title = {Ecuaciones diferenciales ordinarias},
	publisher = {Aguilar},
	year = {1973.},
	series = {Colección Ciencia y técnica.},
	address = {Madrid},
	note = {Translation of: Obyknovennye different︠s︡ial'nye uravenii︠a︡.}
}