For Kummerowia
Akiyama, S., and H. Ohba. 1985. The branching of the inflorescence and vegetative shoot and taxonomy of the genus Kummerowia (Leguminosae). Bot. Mag. Tokyo 98: 137-150.
Isely, D. 1998. Native and naturalized Leguminosae (Fabaceae) of the United States (exclusive of Alaska and Hawaii). Monte L. Bean Life Science Museum, Brigham Young Univ., Provo, UT.