ELTRINGHAM, S K; ATKINSON-WILLES, G L. Recent population changes in British ducks, 1948 to 1960. Wildfowl, [S. l.], p. 40–57, 1960. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155754. Acesso em: 18 dec. 2025.