Higuchi et. al, "Hydrolysis and Dissolution Behavior of a Prolonged-Release Prodrug of Theophylline: 7,7'-Succinylditheophylline,", 1979, Box: 10, Folder: 151. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124575 Accessed May 18, 2024.