Lewis, R. O. (1958). Soil conservation in the Philippines: Terminal report, February 15, 1956-February 1, 1958. United States Operations Mission to the Philippines.
芝加哥风格引文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.
MLA引文Lewis, Ralph O. Soil Conservation in the Philippines: Terminal Report, February 15, 1956-February 1, 1958. United States Operations Mission to the Philippines, 1958.
警告：这些引文格式不一定是100％准确.