Hambach, S. (Law), 1998
Conflicting claims concerning land rights in N.E. Luzon.

Fritsma, S. (Social Geography), 1998
Migration to the Sierra Madre: a study of motives and backgrounds for moving to the forest fringe.

Wout, B. & Rooy, K. de (Phys. Geography), 1998
Soils and Structural Characteristic of the Vegetation on Ultramafic Rock. Northern Sierra Madre, Philippines.

Heuff, M. (Phys. Geography), 1998
Characterization and description of soils under grasslands in NE Luzon.

Kwakkestein, C. (Phys. Geography), 1998
Grassland research and GIS

Goverse, E. (Tropical Forestry), 1998
Socio-economic values of extracted wildlife and changes in time of hunting activities of Agta in two camp site in the municipality of San Mariano, on the west side of the Sierra Madre

Serdiene, I. (Tropical Forestry), 1998
Towards co-management of the Northern Sierra Madre Nature Park: reflection of the process on local level.

Prins, W. (Tropical Forestry), 1998
Organization of community-based forest management in the Northern Sierra Madre, Philippines, with special reference to social sustainability.

Alphen, R. van (Cultural Anthropology), 1998
The Nature of Beings. A study on perceptions and values attached to nature among Agta in the Northern Sierra Madre, Isabela

Bermosa, C. S. (Forestry), 1998
Environmental Factors Influencing Migration Among Bugkalots at Nagtipunan, Quirino

Agatep, W. Q. (Forestry), 1998
Environmental, Socio-Economic and Cultural Adaptation of the Cagayan Agtas in Intervention

Adsuara, N. A. (Forestry), 1998
Farmers' Perception on Indigenous and Introduced Farm Technologies in Selected ISF and Non-ISF in Region 02

Labuguen, M. (Forestry), 1998
Impacts of Local Forest Resources Management Practices on Environmental Integrity: The Case of Sierra Madre Community, San Mariano, Isabela

Bollendorf, S. (Biology), 1998
An interrupted research on indigenous plant knowledge within lowland Dipterocarp forest plots in the Northern Sierra Madre, Luzon.