"The Thermal Decomposition of the Peroxydisulphate Ions in Aqueous Solutions" by Errki Hakoila [signed], Turku, 1963, Box: 1, Folder: 13. Personal papers of Arthur Davidson, PP 661. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/572010 Accessed November 24, 2024.