1. Fischer, E., and Hinkel, H. (1992). Natur Ruandas: La Nature du Rwanda. Rhein-Main Druck, Mainz.
2. Fossey, D. (1974). Observations on the home range of one group of mountain gorillas (Gorilla gorilla beringei). Animal Behaviour. 22:568–581.
3. Fossey, D., and Harcourt, A.H. (1977). Feeding ecology of free-ranging mountain gorilla (Gorilla gorilla beringei). In: Clutton-Brock, T. H. (ed.) Primate Ecology: Studies of Feeding and Ranging Behaviour in Lemurs, Monkeys, and Apes. Academic Press, New York, pp. 415–447.
4. Gerald, C.N. (1995). Demography of the Virunga mountain gorilla (Gorilla gorilla beringei). MSc. Disseration, Princeton University, Princeton, NJ.
5. Goren, et al., (1993). GRASS 4.2 Users Manual. Army Corps of Engineers Construction Engineering Research Laboratories, Champaign, IL.