Krugman, P. R., & Obstfeld, M. (1991). International economics: Theory and policy (2nd ed.). Harper Collins.
芝加哥风格引文Krugman, Paul R., 与 Maurice Obstfeld. International Economics: Theory and Policy. 2nd ed. New York: Harper Collins, 1991.
MLA引文Krugman, Paul R., 与 Maurice Obstfeld. International Economics: Theory and Policy. 2nd ed. Harper Collins, 1991.
警告：这些引文格式不一定是100％准确.