United States. Bureau of Labor Statistics. "Contents," in United States. Bureau of Labor Statistics. "Employment, Hours, and Earnings, United States, 1909-94 : Bulletin of the United States Bureau of Labor Statistics, No. 2445," Employment and Earnings, United States (September 1994) : 6-8. https://fraser.stlouisfed.org/title/189/item/5437/content/pdf/emp_bmark_1909-1994_v2/toc/394214 , accessed on April 18, 2024.