Finch, D. M. (1992). Threatened, endangered, and vulnerable species of terrestrial vertebrates in the rocky mountain region. United States Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station.
Chicago-čujuhus (17. p.)Finch, Deboran M. Threatened, Endangered, and Vulnerable Species of Terrestrial Vertebrates in the Rocky Mountain Region. Fort Collins, Colorado: United States Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, 1992.
MLA-čujuhus (9. p.)Finch, Deboran M. Threatened, Endangered, and Vulnerable Species of Terrestrial Vertebrates in the Rocky Mountain Region. United States Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, 1992.