United States. Bureau of Labor Statistics. "National Compensation Survey: Occupational Wages in the West North Central Census Division, March 2001 : Bulletin of the United States Bureau of Labor Statistics, No. 2553-4," National Compensation Survey: Occupational Wages in the United States (January 2003). https://fraser.stlouisfed.org/title/6084/item/584726, accessed on October 12, 2024.