1. A. A. Morozov, G. V. Novikov, and L. N. Kulikova, Geokhimiya, No. 8, 845 (2001) [Geochem. Int., No. 8, 764 (2001)].
2. G. V. Novikov, L. N. Kulikova, O. Yu. Bogdanova, et al., Zh. Neorg. Khim. 50(12), 1972 (2005) [Russ. J. Inorg. Chem. 50 (12), 1847 (2005)].
3. G. V. Novikov, L. N. Kulikova, O. Yu. Bogdanova, et al., Zh. Neorg. Khim. 51(2), 220 (2006) [Russ. J. Inorg. Chem. 51 (2), 177 (2006)].
4. G. N. Baturin, Oceanic Ores (Nauka, Moscow, 1993) [in Russian].
5. E. S. Bazilevskaya, Chemical-Mineralogical Investigation of Manganese Ores (Nauka, Moscow, 1976) [in Russian].