Higuchi et. al, "Investigation and Development of Protective Ointments I. Development of a Method for Measuring Permeation of Mechanical Barriers,", 1957, Box: 10, Folder: 178. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124602 Accessed June 26, 2024.