Reference

Erik Klop, Thorsten Hahn, Marion Kauth, Sophia Engel, Lucia L. Lastimoza, Eberhard Curio (1999): Diet composition and food provisioning of the Visayan Tarictic Hornbill (Penelopides panini panini) during the breeding season – Ökologie der Vögel. Verhalten Konstitution Umwelt – 21: 389 - 404.