Description: English: Skeleton of a black-casque hornbill's skeleton (male) on display at the Museum of Osteology. Date: 27 May 2014. Source: Own work. Author: Polyoutis.
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/38534605