HARRISON, Jeffery; WARDELL, John. W.A.G.B.I. hand-reared Mallard in the cold spell of 1962-63. Wildfowl, [S. l.], p. 5, 1963. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155190. Acesso em: 17 dec. 2025.