Higuchi et. al, "Studies on Pharmaceutical Powders and the State of Subdivision. I. The Application of Low-Temperature Nitrogen Adsorption Isotherms to the Determination of Surface Areas,", 1949, Box: 11, Folder: 115. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124749 Accessed June 17, 2024.