17. Bernhard, B.A., Garfield, Eugene, and Hammett, L.P. "Specific "Effects in Acid Catalysis by Ion Exchange Resins. III. Some Observations on the Effect of Polyvalent Cations", Journal of the American Chemical Society, 76 (4), p. 991-992, 1954, 1953-1954

17. Bernhard, B.A., Garfield, Eugene, and Hammett, L.P. "Specific "Effects in Acid Catalysis by Ion Exchange Resins. III. Some Observations on the Effect of Polyvalent Cations", Journal of the American Chemical Society, 76 (4), p. 991-992, 1954, 1953-1954, Box: 89, Folder: 30. Eugene Garfield Papers, 2009-036. Science History Institute Archives. https://sciencehistory.libraryhost.com/repositories/3/archival_objects/20792 Accessed November 24, 2024.