1. H. CROZE (1969 ) Elephant Studies in Serengeti Annual Report, 1969. Pp.21 -22 .
2. H. CROZE (1970 ) Elephant Studies in Serengeti Annual Report, 1970. Pp.18 -20 .
3. I. DOUGLAS-HAMILTON (1983 ) Recent factors affecting elephant populations . African Elephant and Rhino Group Newsletter (2). Pp.11 -13 .
4. I. DOUGLAS-HAMILTON (1984 ) Elephant and rhino counts from 1967 to 1981 in selected ranges in Africa . Typescript 26 pages.
5. I. DOUGLAS-HAMILTON (1984 ) Trends in key African elephant populations . Pachyderm (AERSG Newsletter 4). Pp.7 -9 .