O’HALLORAN, J; RIDGWAY, M; HUTCHINSON, C D. A Whooper Swan Cygnus cygnus population wintering at Kilcolman Wildfowl Refuge, Co. Cork, Ireland: trends over 20 years. Wildfowl, [S. l.], p. 1–6, 1993. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154699. Acesso em: 17 dec. 2025.