@book{12057,
	author = {Geis, Aelred D.},
	title = {Black duck distribution, harvest characteristic, and survival},
	publisher = {Bureau of Sport Fisheries and Wildlife,},
	year = {1971},
	series = {Special Scientific Report-Wildlife},
	address = {Washington :},
	note = {Apénd. en 8 microtarjetas}
}