A floristic and ecological study of Matagorda Island. A Natural Area Survey. Office of Research, Lyndon B. Johnson School of Public Affairs, University of Texas at Austin Crawford, D. J. and R. L. Hartman. Chromosome numbers and taxonomic notes for Rocky Mountain Umbelliferae. Hartman, R. L. 1972.
New plant records for Wyoming.
Hartman, R. L. 1972. Research Journal 64, Agric. Station, University of Wyoming. Hartman, R. L. and D. J. Crawford. Hartman, R. L. 1971.