United States. Bureau of Labor Statistics. "Footnotes," in United States. Bureau of Labor Statistics. "Employment, Hours, and Earnings, United States, 1909-84 : Bulletin of the United States Bureau of Labor Statistics, No. 1312-12," Employment and Earnings, United States (March 1985) : 629-629. https://fraser.stlouisfed.org/title/189/item/5434/content/pdf/emp_bmark_1909-1984_v1/toc/51667 , accessed on March 29, 2024.