United States. Bureau of Labor Statistics
, Tillery, Winston L.
and Nagy, Fred R.
Unaffiliated Intrastate and Single-Employer Unions, 1967 : Bulletin of the United States Bureau of Labor Statistics, No. 1640 ,
Washington, D.C:
U.S. Dept. of Labor Bureau of Labor Statistics,
November 1969, https://fraser.stlouisfed.org/title/4868,
accessed on February 27, 2026.