1. Akimoto, S., Syono, Y.: High pressure transformation in MnSiO3. Am. Mineralogist 57, 76?84 (1972)
2. Bertolani, M.: Rocce manganesifere tra le granuliti della valle Strona (Novara). Period. Mineral. 26, 1011?1032 (1967)
3. Borg, I. Y., Smith, D. K.: Calculated X-ray powder patterns for silicate minerals. Mem. Geol. Soo. Amer. 122, 296?315 (1969)
4. Bowen, N. L., Schairer, J. F., Posnjak, E.: The system CaO-FeO-SiO2. Am. J. Sci. 26, 193?284 (1933)
5. Deer, W. A., Howie, R. A., Zussman, J.: Bock forming minerals. London: Longmans 1966