@book{8202,
	author = {Ėlʹsgolʹt︠s︡, L. Ė.},
	title = {Calculus of variations /},
	publisher = {Pergamon Press,},
	year = {1961.},
	series = {International series of monographs on pure and applied mathematics ; },
	address = {Oxford ;},
	note = {Includes index.}
}