Gw mau tau Rujukan dari Ahool

(1999): Cryptozoology A to Z: the encyclopedia of loch monsters, Sasquatch, Chupacabaras, and other authentic mysteries of nature. Fireside, New York.ISBN 0-684-85602-6

(1999): Family Strigidae (typical owls). In: : Handbook of Birds of the World, Volume 5: Barn-owls to Hummingbirds: 76-242, plates 4-20. Lynx Edicions, Barcelona.ISBN 84-87334-25-3

(2003): The Beasts That Hide From Man. Paraview, New York.ISBN 1-931044-64-3