1. Orang-utan extinction threat shortens;Williams;Curr. Biol.,2007
2. The Last Stand of the Orangutan. State of Emergency: Illegal Logging, Fire, and Palm Oil in Indonesia's National Parks,2007
3. Orangutan Population and Habitat Viability Assessment: Final Report;Singleton,2004
4. Our Vanishing Relative. The Status of Wild Orang-utans at the Close of the Twentieth Century;Rijksen,1999
5. Loss of forest cover in Kalimantan, Indonesia, since the 1997–1998 El Niño;Fuller;Conserv. Biol.,2004