1. British Newspaper Archive.
2. Crawfurd, Helen. “The Autobiography of Helen Crawfurd.” Unpublished manuscript, published May 20, 2019. Marx Memorial Library. https://www.marx-memorial-library.org.uk/project/socialist-opposition-ww1/autobiography-helen-crawfurd.
3. Gallacher Memorial Library. National Library of Scotland, Edinburgh.
4. Glasgow Caledonian University Archive Centre, Glasgow.
5. List of organizations and delegates attending the Congress against Colonial Oppression and Imperialism. Brussels. 1927. League Against Imperialism Archives, International Institute of Social History. Accessed May 5, 2019, https://search.iisg.amsterdam/Record/ARCH00804.