by Gladys L. Palmer ; assisted by Ann RatnerIndustrial Research Department, Wharton School of Finance and Commerce, University of Pennsylvania, in cooperation with the Bureau of the Census, U.S. Department of Commerce1944
by Gladys L. Palmer ; assisted by Sophie T. CambriaIndustrial Research Department, Wharton School of Finance and Commerce, University of Pennsylvania, in cooperation with the Bureau of the Census, U.S. Department of Commerce1943