Lehikoinen, E., and J. Lindström. “Chernobyl Radiation Not the Cause of Fatally Delayed Autumn Migration of the Swift Apus Apus in 1986”. Ornis Fennica 65, no. 1 (March 31, 1988): 37–38. Accessed September 16, 2024. https://ornisfennica.journal.fi/article/view/133254.