ELECTRONIC PROPERTIES OF PYROXENES NACRSI<SUB>2</SUB> O<SUB>6</SUB> AND NAFESI<SUB>2</SUB> O<SUB>6</SUB> Статья Streltsov S.V., Kurmaev E.Z., McLeod J., Moewes A., Redhammer G.J. Physical Review B - Condensed Matter and Materials Physics. Том 81. 2010. 045118 с.