United States. Bureau of Labor Statistics. "National Compensation Survey: Chicago-Gary-Kenosha, IL-IN-WI, October 1999 : Bulletin of the United States Bureau of Labor Statistics, No. 3100-76," National Compensation Survey (Wages and Salaries) (August 2000). https://fraser.stlouisfed.org/title/6009/item/582451, accessed on January 6, 2025.