Northern (Abyssinian) Ground Hornbill (Bucorvus abyssinicus) in captivity at African Park, San Diego, California, USA. Photographed on 3 July 2002. A native of Central Africa.www.inaturalist.org/observations/54794459
A monograph of the Bucerotid, or family of the hornbills..[London]Published for the subscribers by the author [printed by Taylor and Francis]1882..biodiversitylibrary.org/page/38534511