"Solvent Extraction of Sewage Secondary Effluents Heterogeneous Equilibrium of Organics and Inorganics", Box: 1, Folder: 60. Personal Papers of Elmer V. McCollum, PP 120. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/292847 Accessed May 05, 2024.