Nest sites and nesting habitats of the Ural Owl Strix uralensis in Finland during the period 1870–1969

Lahti, E. (1972). Nest sites and nesting habitats of the Ural Owl Strix uralensis in Finland during the period 1870–1969. Ornis Fennica, 49(3–4), 91–97. https://ornisfennica.journal.fi/article/view/132842