Rhodin, A. G. J. et al.: Turtles of the World: Annotated Checklist and Atlas of Taxonomy, Synonymy, Distribution, and Conservation Status (9th Ed.) Teoksessa Rhodin, A. G. J. et al. (toim.): Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. Chelonian Research Monographs, 2021, 8. vsk, s. 1–472. doi:10.3854/crm.8.checklist.atlas.v9.2021Artikkelin verkkoversio. (pdf) Viitattu 25.5.2022. (englanniksi)
Rhodin, A. G. J. et al.: Turtles of the World: Annotated Checklist and Atlas of Taxonomy, Synonymy, Distribution, and Conservation Status (9th Ed.) Teoksessa Rhodin, A. G. J. et al. (toim.): Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. Chelonian Research Monographs, 2021, 8. vsk, s. 1–472. doi:10.3854/crm.8.checklist.atlas.v9.2021Artikkelin verkkoversio. (pdf) Viitattu 25.5.2022. (englanniksi)
iucnredlist.org
Tortoise & Freshwater Turtle Specialist Group: Chelonoidis nigerIUCN Red List of Threatened Species. Version 2014.1. 1996. International Union for Conservation of Nature, IUCN, Iucnredlist.org. Viitattu 19.6.2014. (englanniksi)