Smith, Loren M, Larry D Vangilder, Richard T Hoppe, Stephen J Morreale, and I Lehr, Jr Brisbin. 1986. “Effect of Diving Ducks on Benthic Food Resources During Winter in South Carolina, U.S.A”. Wildfowl, January, 136-41. https://tidsskrift.dk/Wildfowl/article/view/154774.