United States. Bureau of Labor Statistics. Division of Wage Statistics , United States. Bureau of Labor Statistics. Division of Wages and Industrial Relations and United States. Bureau of Labor Statistics. Office of Wages and Industrial Relations. "Union Wages and Hours: Local-Transit Operating Employees, July 1, 1969 : Bulletin of the United States Bureau of Labor Statistics, No. 1667," Union Wages and Hours: Local Transit Operating Employees (1970). https://fraser.stlouisfed.org/title/4441/item/498650, accessed on March 16, 2025.