Bloemink, I. (Public Administration), 1990
Land rights and deforestation. The impact of land rights policies on the deforestation complex, N.E. Luzon.

Vermeulen, R. (Tropical Forestry), 1990
Land degradation and farmers in Ifugao.

Frel, T. de (Cultural & Social Anthropology), 1990
The Liwang reforestation project, a study of reforestation and deforestation in N. E. Luzon.