Malthus, T. (1960). On population: Three essays. The new American library.
芝加哥风格引文Malthus, Thomas. On Population: Three Essays. New York: The new American library, 1960.
MLA引文Malthus, Thomas. On Population: Three Essays. The new American library, 1960.
警告：这些引文格式不一定是100％准确.