Quelle und Links
- Marzluff, J. (2019). Common Raven (Corvus corax). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/60808 on 1 October 2019).
- Bauer, Hans-Günter; Bezzel, Einhard; Fiedler, Wolfgang (2005): Das Kompendium der Vögel Mitteleuropas. Aula-Verlag, Wiesbaden
- Kartevorlage: San Jose, 1 April 2007, adapted by Chumwa, 6 May 2008 [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons