1. Bozorth, R.M., Ferromagnetism, Toronto: Van Nostrand, 1951.
2. Danilov, M.A. and Yushkin, N.P., First finding of the Oligocene lava with native iron in the north of the Russian Platform, Dokl. Akad. Nauk SSSR, 1979, no. 9, pp. 1430–1432.
3. Encyclopedia Britannica, 2012.
4. Florenskii, K.P., On the initial stage of differentiation of the Earth’s matter, Geokhimiya, 1965, no. 8, pp. 1–18.
5. Florenskii, K.P., Ivanov, A.V., Il’in, N.P., Petrikova, M.N., and Loseva, L.E., Chemical composition of cosmic spherules from the region of the Tunguska catastrophe and some questions of differentiation of the matter of cosmic bodies, Geokhimiya, 1968, no. 10, pp. 1163–1173.