The Food, Population Fluctuations and Ecology of the Long-Eared Owl 9Asio Otus (L.)) in Norway, 1965, Papers of the Norwegian State Game Research Institute, 2. serie, nr. 23 : 43 pages with illustrations.

1965 Papers of the Norwegian State Game Research Institute 2. serie, nr. 23 : 43 pages with illustrations. Original publication, not a modern reprint. Softbound, a few marks in text margins, good plus condition