@book{22577,
	author = {Larson, Roland E. and Hostetler, Robert P},
	title = {Trigonometry/},
	publisher = {D.C. Heath & Co., },
	year = {1989.},
	address = {Lexington, MA },
	edition = {2a ed.},
	note = {Incluye apéndices e índice.}
}