Regional action plan for the conservation of the cross river gorilla (Gorilla gorilla diehli) - Oates, J.; Sunderland-Groves, J.; Bergl, R.; Dunn, A.; Nicholas, A.; Takang, E.; Omeni, F.; Imong, I.; Fotso, R.; Nkembi, L.; Williamson, L. (IUCN/SSC Primate Specialist Group and Conservation International, 2007)