PERRINS, C M; MCCLEERY, R H. The disadvantage of late-moulting by Mute Swans Cygnus olor. Wildfowl, [S. l.], p. 1–7, 1995. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154676. Acesso em: 17 dec. 2025.