@book{33850,
	author = {Dacorogna, Bernard. and SpringerLink (Online service)},
	title = {Direct Methods in the Calculus of Variations},
	publisher = {Springer New York,},
	year = {2007.},
	series = {Applied Mathematical Sciences,},
	address = {New York, NY :},
	url = {http://dx.doi.org/10.1007/978-0-387-55249-1}
}