I.W.W., General Defense Committee, "On the Outside" Postcard to Honorable Calvin Coolidge, id1060, Box: 11, Folder: 11. Gilbert G. Benjamin, Jr. Subversive Activities Collection, URB-GGB. Special Collections & Archives. https://findingaids.csun.edu/repositories/2/archival_objects/34894 Accessed June 16, 2026.