United States. Bureau of Labor Statistics. "Union Wages and Hours: Local Truckdrivers and Helpers, July 1, 1971 : Bulletin of the United States Bureau of Labor Statistics, No. 1756," Union Wages and Hours : Local Truckdrivers and Helpers (1972). https://fraser.stlouisfed.org/title/3960/item/498895, accessed on December 3, 2024.