Urbatsch, L. E., J. D. Bacon, R. L. Hartman, M. C. Johnston, T. J. Watson, Jr., and G. L. Webster. 1975. Chromosome numbers for North American Euphorbiaceae. Hartman, R. L. 1974. A morphological, cytological, and chemical study. Hartman, R. L. 1973.
New plant records for New Mexico.
Smith, J. and Hartman, R. L. 1973. Mount Livermore-Sawtooth Vegetation Survey. A Natural Area Survey. Office of Research, Lyndon B. Johnson School of Public Affairs, University of Texas at Austin Hartman, R. L. and J. Smith. A floristic and ecological study of Matagorda Island.