ROBERTSON, G J; COOKE, F; GOUDIE, R I; BOYD, W S. The timing of arrival and moult chronology of Harlequin Ducks Histrionicus histrionicus. Wildfowl, [S. l.], p. 147–155, 1997. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154120. Acesso em: 17 dec. 2025.