Hortling, I. (1925). Einige der Ornithologie gewidmete Frühlingstage. Ornis Fennica, 2(4), 99–105. Noudettu osoitteesta https://ornisfennica.journal.fi/article/view/132149
Ornis Fennica is a peer-reviewed international ornithological journal published by BirdLife Finland. We publish analytical and experimental papers on the ecology, behaviour and biogeography of birds. Ornis Fennica is published quarterly with online early practice.