Kirwan GM, Schweizer M, Copete JL.

Multiple lines of evidence confirm that Hume’s Owl Strix butleri (A. O. Hume, 1878) is two species, with description of an unnamed species (Aves: Non-Passeriformes: Strigidae)

. Zootaxa [Internet]. 2015 Jan. 5 [cited 2025 May 1];3904(1):28–50. Available from: https://mapress.com/zt/article/view/zootaxa.3904.1.2