Higuchi et. al, "Studies on Pharmaceutical Powders and the State of Subdivision. IV. The Application of Spray-Drying Techniques to Pharmaceutical Powders,", 1950, Box: 11, Folder: 118. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124752 Accessed June 26, 2024.