Krams, I. A., T. Krams, and J. Cernihovics. “Selection of Foraging Sites in Mixed Willow and Crested Tit Flocks: Rank-Dependent Survival Strategies”. Ornis Fennica 78, no. 1 (March 31, 2001): 1–11. Accessed May 13, 2024. https://ornisfennica.journal.fi/article/view/133542.