Funded by the National Science Foundation PEET program (Partnerships for Enhancing Expertise in Taxonomy)
Gillman, L. S., and W. F. Bailey. 1978. Rocky Mountain Region (R-2). Pages 6-9 in H. D. Brown and P. W. Orr, Forest insect and disease conditions in the United States, 1976. United States Department of Agriculture, Forest Service. vi + 40 p.