1. Hargittai, I., Hargittai, M.: Symmetry through the Eyes of a Chemist, VCH Verlagsgesellschaft, Weinheim and VCH Publishers, New York 1986
2. Fedorov, E. S.: Brief Course in Crystallography, 1910, as cited in Ref. 3
3. Colored symmetry: A Series of Publications from the Institute of Crystallography;AV Shubnikov,1964
4. Hargittai I.: Limits of Perfection. In: Symmetry, Unifying Human Understanding, I. Hargittai, ed., Pergamon Press, New York, Oxford 1986
5. Lord Kelvin: Baltimore Lectures, C. J. Clay and Sons, London 1904