OGILVIE, M A; COOK, W A. British recoveries of Mallard ringed at Borough Fen Decoy, Northamptonshire. Wildfowl, [S. l.], p. 103–110, 1972. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154901. Acesso em: 18 dec. 2025.