HEWSTON, Nigel R. Progress in aviculture by the Wildfowl and Wetlands Trust during 1991. Wildfowl, [S. l.], v. 16, p. 241–242, 1965. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155211. Acesso em: 5 apr. 2026.