Paatela, J., and L. Kaila. “On the Expansion of Blyth´s Reed Warbler (Acrocephalus Dumetorum) into Finland”. Ornis Fennica 37, no. 1–2 (July 1, 1960): 1–11. Accessed April 20, 2025. https://ornisfennica.journal.fi/article/view/132645.