Friedman, I. S. (1968). The developing countries in the past twenty years: Growth transformation and problems.
芝加哥风格引文Friedman, Irving S. The Developing Countries in the Past Twenty Years: Growth Transformation and Problems. [s.l. : s.n.], 1968.
MLA引文Friedman, Irving S. The Developing Countries in the Past Twenty Years: Growth Transformation and Problems. 1968.
警告：这些引文格式不一定是100％准确.