A study of a change from one shift of 9 hours to two shifts of 6 hours each - Best, Ethel L. (Ethel Lombard) (Washington, U.S. Govt. print. off., 1934)
At head of title: U.S. Department of labor. Fransis Perkins, secretary. Woman's bureau. Mary Anderson, director.
Keywords: Hours of labor; Women -- Employment; Fatigue