Lewis, Richard H. , United States. Bureau of Labor Statistics and Winegarden, Calman R. (Calman Robert). Employment Outlook in Machine Shop Occupations : Bulletin of the United States Bureau of Labor Statistics, No. 895 , Washington, D.C: U.S. Govt. Print. Off., 1947, https://fraser.stlouisfed.org/title/4346, accessed on November 14, 2024.