BirdLife International (2012). Upupa epops. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.نسخة محفوظة 2013-11-11 في Wayback Machine
web.archive.org
BirdLife International (2012). Upupa epops. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.نسخة محفوظة 2013-11-11 في Wayback Machine