United States. Bureau of Labor Statistics. "Wage Chronology: Bituminous Coal Mine Operators and United Mine Workers of America, October 1933-November 1974 : Bulletin of the United States Bureau of Labor Statistics, No. 1799,"
Wage Chronology: Bituminous Coal Mine Operators and United Mine Workers of America
(1973).
https://fraser.stlouisfed.org/title/4650/item/499043, accessed on April 25, 2025.
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