HANSON, W. R.; SOIKKELI, M. Group size and sex ratios among Finnish Black Grouse. Ornis Fennica, [S. l.], v. 61, n. 3, p. 65–68, 1984. Disponível em: https://ornisfennica.journal.fi/article/view/133148. Acesso em: 19 sep. 2024.