@book{7089,
	author = {Gelʹfand, I. M. and Fomin, S. V.},
	title = {Calculus of variations /},
	publisher = {Prentice-Hall,},
	year = {c1963.},
	address = {Englewood Cliffs :},
	edition = {Revised English ed. /},
	note = {Includes index.}
}