Bursa bursa-pastoris and Bursa heegeri biotypes and hybrids - Shull, George Harrison, 1874- (Washington, D.C. : Carnegie Institution of Washington, 1909)
"Papers of the Station for Experimental Evolution, no.12".
"Literature cited": p.57.
Keywords: Bursa bursa -- pastoris; Bursa heegeri; Hybridization, Vegetable