Krams, I. “Rank-Dependent Fattening Strategies of Willow Tit Parus Montanus and Crested Tit P. Cristatus Mixed Flock Members”. Ornis Fennica 75, no. 1 (March 31, 1998): 19–26. Accessed November 22, 2024. https://ornisfennica.journal.fi/article/view/133477.