Funded by the National Science Foundation PEET program (Partnerships for Enhancing Expertise in Taxonomy)
Berisford, C. W., H. M. Kulman, R. L. Pienkowski, and H. J. Heikkenen. 1971. Factors affecting distribution and abundance of hymenopterous parasites of Ips spp. bark beetles in Virginia (Coleoptera: Scolytidae). Canadian Entomologist 103(2):235-239.