HELMINEN, M. Occurrence of the Red-flanked Bluetail (Tarsiger cyanurus) in Finland and some remarks concerning its expansion to the west. Ornis Fennica, [S. l.], v. 35, n. 2–3, p. 51–64, 1958. Disponível em: https://ornisfennica.journal.fi/article/view/132621. Acesso em: 18 may. 2024.