Allen, J.; Tilley, D. 2014. Plant guide for American vetch (Vicia americana). Aberdeen, ID: U.S. Department of Agriculture, Natural Resources Conservation Service, Plant Materials Center. 3 p.
Allen, J.; Tilley, D. 2014. Plant guide for American vetch (Vicia americana). Aberdeen, ID: U.S. Department of Agriculture, Natural Resources Conservation Service, Plant Materials Center. 3 p.