Philippine Council For Agriculture, Forestry and Natural Resources Research And Development, & National Science and Technology Authority. (1986). State of the art non-metallic minerals: Fertilizer research. Philippine Council for Agriculture and Resources Research and Development.

Philippine Council For Agriculture, Forestry and Natural Resources Research And Development, and National Science and Technology Authority. State of the Art Non-metallic Minerals: Fertilizer Research. Los Banos, Laguna: Philippine Council for Agriculture and Resources Research and Development, 1986.

Philippine Council For Agriculture, Forestry and Natural Resources Research And Development, and National Science and Technology Authority. State of the Art Non-metallic Minerals: Fertilizer Research. Philippine Council for Agriculture and Resources Research and Development, 1986.