Watkins, G. S. (1922). An introduction to the study of labor problems. Thomas Y. Crowell Co..
Lua i Stíl Chicago (17ú heag.)Watkins, Gordon S. An Introduction to the Study of Labor Problems. New York: Thomas Y. Crowell Co., 1922.
Lua MLA (8ú heag.)Watkins, Gordon S. An Introduction to the Study of Labor Problems. Thomas Y. Crowell Co., 1922.
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