1. 1W. L. Bragg , Atomic Structure of Minerals , pp.83 -90 . Cornell Univ. Press, Ithaca, N. Y., 1937 . 83 pp.Ceram. Abs., 17 [6 ] 83 (1937 ).
2. The cristobalite structures
3. Cristobalite structures; II, Low-cristobalite
4. 4P. P. Ewald, and C. Hermann , Strukturbericht , 1913 , p.202 . Akad. Verlags., Leipzig, 1913 .
5. 5C. Gottfried, and F. Shossberger , Strukturbericht, Vol. III , 1933 , pp.294 -300 . Akad. Verlags., Leipzig, 1933 .