Park, C.-R., W.-S. Lee, and T. Hino. “Temporal Changes of Foraging Niche Among Breeding Tits (Paridae) in a Korean Temperate Deciduous Forest”. Ornis Fennica, vol. 82, no. 3, Sept. 2005, pp. 81–88, https://ornisfennica.journal.fi/article/view/133636.