Higuchi et. al, "Ion Pair Extraction of Pharmaceutical Amines. Role of Dipolar Solvating Agents in Extraction of Dextromethorphan,", 1967

Higuchi et. al, "Ion Pair Extraction of Pharmaceutical Amines. Role of Dipolar Solvating Agents in Extraction of Dextromethorphan,", 1967, Box: 10, Folder: 191. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124615 Accessed February 16, 2026.