1. Biological control of Rumen obtusifolius L. by goat grazing;Sakanooue;Jpn. Agric. Res. Q.,1995
2. Letters following this symbol are a WSSA-approved computer code from Composite List of Weeds, Revised 1989. Available from WSSA, 810 East 10th Street, Lawrence, KS 66044-8897.
3. Vascular flora of Ransom, Richland, and Sargent counties, North Dakota;Seiler;Prairie Nat.,1985
4. Tecator Co., Hoganas, Sweden.