identification guide to theducks, geese and swans of the world. London: Christopher Helm. 1987. ISBN 0-7470-2201-1. Jobling, James A. The Helm Dictionary of
to theducks, geese and swans of the world. Christopher Helm, London. ISBN 0-7470-2201-1 Duck of the Month – Lesser Scaup (页面存档备份,存于互联网档案馆). Ducks Unlimited