Watkins, G. S. An introduction to the study of labor problems. Crowell.
芝加哥风格引文Watkins, Gordon S. An Introduction to the Study of Labor Problems. New York, [c1922]: Crowell.
MLA引文Watkins, Gordon S. An Introduction to the Study of Labor Problems. Crowell.
警告：这些引文格式不一定是100％准确.