United States. Bureau of Labor Statistics , Crowley, Michael F. and Abramson, Elinor W. Technician Manpower, 1966-80 : Bulletin of the United States Bureau of Labor Statistics, No. 1639 , Washington, D.C: U.S. G.P.O., March 1970, https://fraser.stlouisfed.org/title/4852, accessed on December 21, 2024.