1979
Marley, G. 1979. Status and distribution for Sclerocactus whipplei var. heilii. Bureau of Land Management. 77 p.
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Sclerocactus cloveriae
Marley, G. 1979. Status and distribution for Sclerocactus whipplei var. heilii. Bureau of Land Management. 77 p.
Ladyman, J. 1995. Botanical survey for Gilia formosa along seismic line #3, in San Juan County. September 3-5, 1995. . 6 p.
Sivinski, R. 1997. Endangered Plant Study. Sante Fe, NM: New Mexico Forestry Division; Performance Report E-9-11. 97p.
Porter, J.M. and L.M. Prince. 2011. Report on the evidence supporting generic and species circumscriptions in the genus Sclerocactus with recommendations for a biologically justified taxonomy that will be stable into the future; and biological assessments
East, M. 2015. Database of surveys for Brack's cactus (Sclerocactus cloveriae ssp. brackii) in northwestern New Mexico. Natural Heritage New Mexico.