Philippines (Republic) Bureau of Soil Conservation. Soil erosion. Office of Agricultural Information.
Citazione stile Chigago Style (17a edizione)Philippines (Republic) Bureau of Soil Conservation. Soil Erosion. [Manila: Office of Agricultural Information.
Citatione MLA (9a ed.)Philippines (Republic) Bureau of Soil Conservation. Soil Erosion. Office of Agricultural Information.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.