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Cruz, Gladys A., Juan M. Pulhin, Lucrecio L. Rebugio, and Florencia B. Pulhin. Sustainable Mountain Ecosystems: Philippines' Challenge for the 21st Century : Proceedings of Forum on Sustainable Mountain Ecosystems. College, Laguna: College of Forestry and Natural Resources, University of the Philippines Los Banos, 1998.

Cruz, Gladys A., et al. Sustainable Mountain Ecosystems: Philippines' Challenge for the 21st Century : Proceedings of Forum on Sustainable Mountain Ecosystems. College of Forestry and Natural Resources, University of the Philippines Los Banos, 1998.