United States. Bureau of Labor Statistics. "Union Wages and Hours: Motortruck Drivers and Helpers, July 1, 1966 : Bulletin of the United States Bureau of Labor Statistics, No. 1548," Union Wages and Hours : Local Truckdrivers and Helpers (1967). https://fraser.stlouisfed.org/title/3960/item/498296, accessed on October 13, 2024.