Funded by the National Science Foundation PEET program (Partnerships for Enhancing Expertise in Taxonomy)
Flake, H. W., and C. J. Germain. 1970. Southwestern States (R-3). Pages 23-25 in A. E. Landgraf, Forest insect and disease conditions in the United States 1969. United States Department of Agriculture, Forest Service. vi + 40 p.