ATKINSON-WILLES, G L. The mid-winter distribution of wildfowl in Europe, northern Africa and south-west Asia, 1967 and 1968. Wildfowl, [S. l.], p. 98–111, 1969. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155558. Acesso em: 18 dec. 2025.