Górski, Andrzej, Jacek J. Nowakowski, and Jerzy Banbura. “Variation in Egg-Size Traits of the European Roller (Coracias Garrulus) in Eastern Poland”. Ornis Fennica 92, no. 4 (December 31, 2015): 213–220. Accessed November 23, 2024. https://ornisfennica.journal.fi/article/view/133881.