Higuchi et. al, "Oxidation of Thioethers to Sulfoxides by Iodine. II. Catalytic Role of Some Carboxylic Acid Anions,", 1968, Box: 11, Folder: 27. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124661 Accessed December 21, 2024.