Roth, Terri L., O'Brien, J. K., McRae, M. A., Bellem, A. C., Romo, S. J., Kroll, J. L., and Brown, Janine L. 2001. "
Ultrasound and endocrine evaluation of the ovarian cycle and early pregnancy in the Sumatran rhinoceros (Dicerorhinus sumtrensis)."
Reproduction. 121:139–149.