SAMMALISTO, L. Secondary intergradation of the Blue-headed and Grey-headed Wagtails (Motacilla f. flava L. and Motacilla f, thunbergi Billb.) in South Finland. Ornis Fennica, [S. l.], v. 33, n. 1, p. 1–19, 1956. Disponível em: https://ornisfennica.journal.fi/article/view/132588. Acesso em: 25 dec. 2024.