Johnsgard, P. A. (1986). Birds of the Rocky Mountains: With particular reference to national parks in the Northern Rocky Mountain Region. Colorado Assoc. Univ. Pr.
Chicago-Zitierstil (17. Ausg.)Johnsgard, Paul A. Birds of the Rocky Mountains: With Particular Reference to National Parks in the Northern Rocky Mountain Region. Boulder, Colo: Colorado Assoc. Univ. Pr, 1986.
MLA-Zitierstil (9. Ausg.)Johnsgard, Paul A. Birds of the Rocky Mountains: With Particular Reference to National Parks in the Northern Rocky Mountain Region. Colorado Assoc. Univ. Pr, 1986.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.