Roth, T.L.; O’Brien, J.K. 2000. Post-coital sperm recovery and cryopreservation in the Sumatran rhinoceros (Dicerorhinus sumatrensis) and application to gamete rescue in the African black rhinoceros (Diceros bicornis).
Journal of Reproduction and Fertility 118 (2): 263-271, figs. 1-2, tables 1-3.