Funded by the National Science Foundation PEET program (Partnerships for Enhancing Expertise in Taxonomy)
Tripp, H. A., R. E. Stevenson, and J. A. Baranyay. 1967. Alberta-Northwest Territories-Yukon Region. Pages 95-107. Canada Department of Forestry and Rural Development, Forestry Branch, Forest Insect and Disease Survey, Annual Report 1966. 142 p.