BEEKMAN, Jan H; DIRKSEN, Sjoerd; SLAGBOOM, Teus H. Population size and breeding success of Bewick’s Swans wintering in Europe in 1983-4. Wildfowl, [S. l.], p. 5–12, 1985. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155040. Acesso em: 17 dec. 2025.