Funded by the National Science Foundation PEET program (Partnerships for Enhancing Expertise in Taxonomy)
Hastings, A. R., and J. T. O'Brien. 1973. Northeastern states (R-9). Pages 57-68 in D. P. Graham and J. F. Chansler, Forest insect and disease conditions in the United States, 1972. United States Department of Agriculture, Forest Service. vi + 72 p.