1. Gibbons and brachiation;Andrews,1976
2. The Quaternary geomorphological history of western Malesia and lowland forest phytogeography;Ashton,1972
3. Nature conservation and wildlife management in Indonesia;Basjarudin,1973
4. Field research on gibbons, siamangs, and orangutans: an historical, geographical and bibliographical listing;Baldwin;Primates,1974
5. The social behaviour of gibbons in relation to a conservation program;Berkson,1971