Jabbonski, P. G., and S. D. Lee. “Foraging Niche Differences Between Species Are Correlated With Body- Size Differences in Mixed-Species Flocks Near Soul, Korea”. Ornis Fennica 76, no. 1 (March 31, 1999): 17–23. Accessed May 18, 2024. https://ornisfennica.journal.fi/article/view/133494.