Sri Suci Utami

A simple alternative to line transects of nests for estimating orangutan densities

Serge A. Wich, S. Wich, C. Schaik, 2005, Primates.

Male bimaturism and reproductive success in Sumatran orang-utans

Benoit Goossens, Michael William Bruford, B. Goossens, 2002 .