1. Papua New Guinea: Economic Situation and Outlook;Stein,1991
2. The Papua New Guinea Economy: Prospects for Recovery, Reform and Sustained Growth;Fallon,1992
3. The proportion of the population estimated to be resident in rural villages was 88% in 1966, 82% in 1971, and 81% in 1980
4. The origins of Oceanic agriculture;Yen;Archaeology and Physical Anthropology in Oceania,1973
5. Late Quaternary vegetational history of the Enga District of upland Papua New Guinea;Walker;Philosophical Transactions of the Royal Society, B,1979