Jeheskel Shoshani, "Order Proboscidea," Mammal Species of the World, (3rd ed.), Volume 1, Don E. Wilson & DeeAnn M. Reeder (ed.), Johns Hopkins University Press, 2005, Page 90-91.
Choudhury, A., Lahiri Choudhury, D.K., Desai, A., Duckworth, J.W., Easa, P.S., Johnsingh, A.J.T., Fernando, P., Hedges, S., Gunawardena, M., Kurt, F., Karanth, U., Lister, A., Menon, V., Riddle, H., Rübel, A. & Wikramanayake, E. (IUCN SSC Asian Elephant Specialist Group) 2008. Elephas maximus. The IUCN Red List of Threatened Species 2008: e.T7140A12828813. https://doi.org/10.2305/IUCN.UK.2008.RLTS.T7140A12828813.en. Downloaded on 10 April 2020.
Gopala, A., Hadian, O., Sunarto, ., Sitompul, A., Williams, A., Leimgruber, P., Chambliss, S.E. & Gunaryadi, D. 2011. Elephas maximus sumatranus. The IUCN Red List of Threatened Species 2011: e.T199856A9129626. https://doi.org/10.2305/IUCN.UK.2011-2.RLTS.T199856A9129626.en. Downloaded on 10 April 2020.
UNEP (2020). Elephas maximus. The Species+ Website. Nairobi, Kenya. Compiled by UNEP-WCMC, Cambridge, UK. Available at: www.speciesplus.net. (downroad 09/04/2020)
