We have information from several sources:
Hairy Vetch: Alternative Field Crops Manual, University of Wisconson Cooperative Extension Service, University of Minnesota Extension Service, Center for Alternative Plant & Animal Products
New Crops: Solutions for Global ProblemsNoel Vietmeyer
Magness, J.R., G.M. Markle, C.C. Compton. 1971. Food and feed crops of the United States.