Não informado. Philippine Journal of Soils. Department of Agriculture and Natural Resources.
Cita Chicago Style (17a ed.)Não informado. Philippine Journal of Soils. Manila: Department of Agriculture and Natural Resources.
Cita MLA (8a ed.)Não informado. Philippine Journal of Soils. Department of Agriculture and Natural Resources.
Precaución: Estas citas no son 100% exactas.