KOLUNEN, H.; PEIPONEN, V. A. Delayed autumn migration of the Swift Apus apus from Finland in 1986. Ornis Fennica, [S. l.], v. 68, n. 3, p. 81–92, 1991. Disponível em: https://ornisfennica.journal.fi/article/view/133319. Acesso em: 18 touko. 2024.