September 4th is Labor Day in the USA, accordingly here are some links about librarian unionism as well as library services to unions:
Latham, J. M. (2011). Memorial Day to Memorial Library: The South Chicago Branch Library as cultural terrain, 1937–1947. Libraries & the Cultural Record, 46(3), 321–342.
Union Library Workers blog: http://unionlibraryworkers.blogspot.com/
Daniel, Dominqiue. “Knowledge is Power: The Rise and Fall of the Libraries of the United Automobile Workers’ Union,” Libraries: Culture, History, and Society 3 no. 1 (2019): 72-96. DOI: 10.5325/libraries.3.1.0072 [Available for free to LHRT members].
Biblo, Herbert. “Librarians and Trade Unionism: A Prologue.” (1976). Library Trends 25, no. 2 (1976).
https://www.ideals.illinois.edu/items/6870/bitstreams/25239/object?dl=1
McCook, Kathleen de la Peña. “Unions in Public and Academic Libraries.” Adopted from Encyclopedia of Library and Information Sciences (3rd ed.) New York: Taylor and Francis (2010).
https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=1107&context=si_facpub
ALA Statement–Unions and Collective Bargaining
https://www.ala.org/tools/atoz/unions

Union Library Workers blog: http://unionlibraryworkers.blogspot.com/
Latham, J. M. (2011). Memorial Day to Memorial Library: The South Chicago Branch Library as cultural terrain, 1937–1947. Libraries & the Cultural Record, 46(3), 321–342.