Spencer Prokop

<strong>Quelle:</strong> <a href="//commons.wikimedia.org/w/index.php?title=User:Ulrich_prokop&amp;action=edit&amp;redlink=1" class="new" title="User:Ulrich prokop (page does not exist)">Ulrich prokop</a> - BNA - Birds of America Online: Rasmussen, Justin Lee, Spencer G. Sealy and Richard J. Cannings. 2008. Northern Saw-whet Owl (Aegolius acadicus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: <a rel="nofollow" class="external free" href="http://bna.birds.cornell.edu/bna/species/042">http://bna.birds.cornell.edu/bna/species/042</a>