Tanskanen, Antti, Rauno A Yrjölä, Ulrike Baum, Sakari Tanskanen, and Jörgen Eriksson. “How Many Observation Days Are Needed to Reliably Describe Bird Migration?”. Ornis Svecica 28, no. 1 (January 1, 2018): 3–13. Accessed April 23, 2024. https://journals.lub.lu.se/os/article/view/19519.