
Ornitólogo Medieval Frederico II

http://www.jstor.org/

http://links.jstor.org/sici?sici=0013-8266%28192107%2936%3A143%3C334%3AT%27AVCA%3E2.0.CO%3B2-U&size=LARGE
http://www.fh-augsburg.de/~harsch/Chronologia/Lspost13/FridericusII/fri_arsp.html
http://online-media.uni-marburg.de/germanistik/gloning/at/de-arte-venandi-cum-avibus-1.pdf