Não informado. Philippine Journal of Soils. Department of Agriculture and Natural Resources.
Citação do estilo Chicago (17ª ed.)Não informado. Philippine Journal of Soils. Manila: Department of Agriculture and Natural Resources.
Citação MLA (8ª ed.)Não informado. Philippine Journal of Soils. Department of Agriculture and Natural Resources.
אזהרה: ציטוטים אלה לעיתים לא מדויקים ב 100%.