@book{11127,
	author = {Brechtken-Manderscheid, Ursula and Engstrom, P. G.},
	title = {Introduction to the calculus of variations},
	publisher = {Chapman & Hall/CRC Press,},
	year = {1991},
	series = {Chapman & Hall Mathematics},
	address = {London:},
	note = {"Translated from the German by P. G. Engstrom"}
}