@book{40440,
	author = {Fox, Charles,},
	title = {An introduction to the calculus of variations /},
	publisher = {Dover Publications,},
	year = {1987.},
	address = {New York :},
	note = {Reprint. Originally published: London : Oxford University Press, 1950 (1963 printing).},
	url = {http://www.loc.gov/catdir/description/dover033/87020112.html}
}