EVANS, Mary E. Population composition, and return according to breeding status, of Bewick’s Swans wintering at Slimbridge, 1963 to 1976. Wildfowl, [S. l.], v. 30, p. 118–128, 1979. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154131. Acesso em: 19 apr. 2026.