OGILVIE, M A; COOK, W A. Differential migration of the sexes and other aspects of the recovery overseas of mallard ringed at Borough Fen Decoy, Northamptonshire. Wildfowl, [S. l.], n. 22, p. 89–97, 1971. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155410. Acesso em: 18 dec. 2025.