Landgren, C., State University. Extension Service, O., State University. Cooperative Extension, W., of Idaho. Cooperative Extension System, U., & States. Department of Agriculture, U. (1996). Calibrating and using backpack sprayers. : [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.