Simpson, J. B. (1900). Capital and labour in coal mining during the past two hundred years. R. Robinson.
芝加哥风格引文Simpson, John Bell. Capital and Labour in Coal Mining During the Past Two Hundred Years. Newcastle-upon-Tyre: R. Robinson, 1900.
MLA引文Simpson, John Bell. Capital and Labour in Coal Mining During the Past Two Hundred Years. R. Robinson, 1900.
警告：这些引文格式不一定是100％准确.