Langley, K. M. (1970). The economics of the international petroleum industry and the economy of the Philippines. Philippine Review of Economics and Business (formerly The Philippine Review of Business and Economics).
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)Langley, Kathleen M. "The Economics of the International Petroleum Industry and the Economy of the Philippines." Philippine Review of Economics and Business (formerly The Philippine Review of Business and Economics) 1970.
Trích dẫn kiểu MLA (xuất bản lần thứ 9)Langley, Kathleen M. "The Economics of the International Petroleum Industry and the Economy of the Philippines." Philippine Review of Economics and Business (formerly The Philippine Review of Business and Economics), 1970.
Cảnh báo: Các trích dẫn này có thể không phải lúc nào cũng chính xác 100%.