Fitzsimmons, Jim P., L. C Burrill, Oregon State University. Extension Service, Washington State University. Cooperative Extension, University of Idaho. Cooperative Extension System, United States. Department of Agriculture, and Pacific Northwest Cooperative Extension. 1993. Red Sorrel, Rumex Acetosella L. : [Corvallis, Or.] : Oregon State University Extension Service ; [Olympia, Wash.] : Washington State University Cooperative Extension ; [Moscow, Idaho] : University of Idaho Cooperative Extension System ; [Washington, D.C.] : U.S. Dept. of Agriculture.