Petroleum Institute of the Philippines, I. (1971). The oil industry in crisis. s.n.
芝加哥风格引文Petroleum Institute of the Philippines, Inc. The Oil Industry in Crisis. Manila: s.n, 1971.
MLA引文Petroleum Institute of the Philippines, Inc. The Oil Industry in Crisis. s.n, 1971.
警告：这些引文格式不一定是100％准确.