@book{206011,
	author = {Tippens, Paul E.},
	title = {Física},
	publisher = {McGraw-Hill},
	year = {2001.},
	address = {México},
	edition = {6th ed.},
	note = {Includes index.},
	url = {http://www.loc.gov/catdir/description/mh031/99052055.html}
}