United States. Bureau of Labor Statistics.
Techniques of Preparing Major BLS Statistical Series : From the Monthly Labor Review of the Bureau of Labor Statistics, September, October, and November 1949, and January, February, March, and April 1950 Issues : Bulletin of the United States Bureau of Labor Statistics, No. 993 ,
Washington, D.C:
G.P.O.,
1950, https://fraser.stlouisfed.org/title/4388,
accessed on January 5, 2026.