Marjakangas, A. “A Singing Chaffinch Fringilla Coelebs in Female Plumage Paired With Another Female-Plumaged Chaffinch”. Ornis Fennica 58, no. 2 (July 1, 1981): 90–91. Accessed November 23, 2024. https://ornisfennica.journal.fi/article/view/133068.