United States. Bureau of Labor Statistics. "Union Wages and Hours: Motortruck Drivers and Helpers, July 1, 1967 : Bulletin of the United States Bureau of Labor Statistics, No. 1591," Union Wages and Hours : Local Truckdrivers and Helpers (1968). https://fraser.stlouisfed.org/title/3960/item/498417, accessed on November 17, 2024.