Integrated Taxonomic Information System (ITIS): Ninox connivens (TSN 555477)itis.gov. Viitattu 4.8.2011. (englanniksi)
iucnredlist.org
BirdLife International: Ninox connivensIUCN Red List of Threatened Species. Version 2013.2. 2012. International Union for Conservation of Nature, IUCN, Iucnredlist.org. Viitattu 15.5.2014. (englanniksi)