SPRAY, C J; BAYES, K. The effect of neck collars on the behaviour, weight and breeding success of Mute Swans Cygnus olor. Wildfowl, [S. l.], p. 49–57, 1992. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155370. Acesso em: 17 dec. 2025.