Chicago

William, R. D., Kenneth N Brown, Oregon State University. Extension Service, Washington State University. Cooperative Extension, University of Idaho. Cooperative Extension System, and United States. Department of Agriculture. 1987. Managing Weeds and Vegetation In Christmas Trees. : [Corvallis, Or.] : Oregon State University Extension Service ; [Pullman, Wash.] : Washington State University Cooperative Extension ; [Moscow, Idaho] : University of Idaho Cooperative Extension System ; [Washington, D.C.] : U.S. Dept. of Agriculture.