Lewis, R. O. (1958). Soil conservation in the Philippines: Terminal report, February 15, 1956-February 1, 1958. United States Operations Mission to the Philippines.
Citazione stile Chigago Style (17a edizione)Lewis, Ralph O. Soil Conservation in the Philippines: Terminal Report, February 15, 1956-February 1, 1958. [Manila]: United States Operations Mission to the Philippines, 1958.
Citatione MLA (9a ed.)Lewis, Ralph O. Soil Conservation in the Philippines: Terminal Report, February 15, 1956-February 1, 1958. United States Operations Mission to the Philippines, 1958.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.