Hudson, H. D. (1952). The Progressive Mine Workers of America: A study in rival unionism. University of Illinois.
Lua i Stíl Chicago (17ú heag.)Hudson, Harriet D. The Progressive Mine Workers of America: A Study in Rival Unionism. Urbana: University of Illinois, 1952.
Lua MLA (8ú heag.)Hudson, Harriet D. The Progressive Mine Workers of America: A Study in Rival Unionism. University of Illinois, 1952.
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