Soikkeli, M. (1964) “Uber das uberwintern und die Nahrung der Waldohreule (Asio otus) in Sudwestfinnland 1962/63”, Ornis Fennica, 41(2), pp. 37–40. Available at: https://ornisfennica.journal.fi/article/view/132692 (Accessed: 23November2024).