HORTLING, I. Eine ganz eigentümliche individuelle Variation des Seeadlers Haliaeetus albicilla (L). Ornis Fennica, [S. l.], v. 4, n. 1, p. 16–19, 1927. Disponível em: https://ornisfennica.journal.fi/article/view/132177. Acesso em: 27 dec. 2024.