http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
cytogenetical study of a 40-chromosome hybrid of Sorghum vulgare X Sorghum halepense
"The material used in this study came from a cross between Johnson grass and ... Blackhull Kafir."--page 6.
M.S. in Genetics A. & M. College of Texas.