1. 7th Communication on Magnetochemical Investigations of Chromia-mixed-Oxides, as for the 6th comm. see this journal 375, 217 (1970).
2. Bunsen's method see: and Maßanalyse, 8th ed., p. 97, Berlin 1959.
3. ASTM = American Standards and Testing Materials.
4. Solid Oxides and Hydroxides of Manganese1