Gemmill, P. F. (1948). Economics: Principles and problems (3rd ed. vol. 1 & 2.). Harper.
芝加哥风格引文Gemmill, Paul F. Economics: Principles and Problems. 3rd ed. vol. 1 & 2. New York: Harper, 1948.
MLA引文Gemmill, Paul F. Economics: Principles and Problems. 3rd ed. vol. 1 & 2. Harper, 1948.
警告：这些引文格式不一定是100％准确.