1. P. Pascal, Nouveau Traité de Chimie Minérale, Tome II, Masson, Paris, 1966, p. 702.
2. V.V. Valkov, A. Deneva, D. Stavrakeva, Proc. Seventh Int. Congr. Chem. Cem., Paris, France, vol. 3, 1980, V/98–V/101.
3. Preparation and Properties of Ferrospinels Containing Ni3+