Integrated Taxonomic Information System (ITIS): Bubo capensis (TSN 555407)itis.gov. Viitattu 3.5.2012. (englanniksi)
iucnredlist.org
BirdLife International: Bubo capensisIUCN Red List of Threatened Species. Version 2013.2. 2012. International Union for Conservation of Nature, IUCN, Iucnredlist.org. Viitattu 16.5.2014. (englanniksi)