Higuchi and Miki, "Reversible Formation of Amides from Free Carboxylic Acid and Amine in Aqueous Solution. A Case of Neighboring Group Faciliation,", 1961, Box: 11, Folder: 87. Personal papers of Takeru Higuchi, PP 359. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/124721 Accessed January 02, 2025.