Higuchi and Pitman, "Caffeine Complexes with Low Water Solubility Synthesis and Dissolution Rates of 1:1 and 1:2 Caffeine-Gentisic Acid Complexes,", 1973

Higuchi and Pitman, "Caffeine Complexes with Low Water Solubility Synthesis and Dissolution Rates of 1:1 and 1:2 Caffeine-Gentisic Acid Complexes,", 1973, Box: 10, Folder: 54. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124478 Accessed December 25, 2025.