United States. Bureau of Labor Statistics. "National Compensation Survey: Washington-Baltimore, DC-MD-VA-WV, April 2006 : Bulletin of the United States Bureau of Labor Statistics, No. 3135-35," National Compensation Survey (Wages and Salaries) (January 2007). https://fraser.stlouisfed.org/title/6009/item/582947, accessed on January 15, 2025.