MLA

Fitzsimmons, Jim P, et al. 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, 1993.