J. E. Swenson and Y. Fujimaki, “Hazel Grouse Bonasa bonasia group sizes and sex rations in Japan and Sweden”, Ornis Fenn, vol. 71, no. 2, pp. 43–46, Jul. 1994, Accessed: Nov. 29, 2025. [Online]. Available: https://ornisfennica.journal.fi/article/view/133391