Higuchi et. al, "Investigation and Development of Protective Ointments IV. The Influence of Active Fillers on the Permeability of Semisolids,", 1960, Box: 10, Folder: 181. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124605 Accessed June 16, 2024.