"Connecticut's Endangered, Threatened and Special Concern Species 2015". State of Connecticut Department of Energy and Environmental Protection Bureau of Natural Resources. Retrieved 2 January 2017. (Note: This list is newer than the one used by plants.usda.gov and is more up-to-date.)
Delgado-Salinas, Alfonso; Bibler, Ryan; Lavin, Matt (2006-10-01). "Phylogeny of the Genus Phaseolus (Leguminosae): A Recent Diversification in an Ancient Landscape". Systematic Botany. 31 (4): 779–791. doi:10.1600/036364406779695960. ISSN0363-6445.
Allard, H. A. (1947). "The ecology of the wild kidney bean Phaseolus polystachios (L.) BSP". Journal of the Washington Academy of Sciences. 37 (9): 306–309. JSTOR24531921.
Delgado-Salinas, Alfonso; Bibler, Ryan; Lavin, Matt (2006-10-01). "Phylogeny of the Genus Phaseolus (Leguminosae): A Recent Diversification in an Ancient Landscape". Systematic Botany. 31 (4): 779–791. doi:10.1600/036364406779695960. ISSN0363-6445.