@book{50981,
	author = {Dacorogna, Bernard},
	title = {Introduction to the calculus of variations /},
	publisher = {Imperial College Press ;},
	year = {c2009},
	address = {London :},
	edition = {2nd ed.},
	note = {Includes bibliographical references (p. 275-281) and index},
	url = {http://www.loc.gov/catdir/toc/ecip0827/2008038721.html}
}