Watkins, G. S. An introduction to the study of labor problems. Crowell.
Lua i Stíl Chicago (17ú heag.)Watkins, Gordon S. An Introduction to the Study of Labor Problems. New York, [c1922]: Crowell.
Lua MLA (9ú heag.)Watkins, Gordon S. An Introduction to the Study of Labor Problems. Crowell.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.