1. J. Donohue: The Structures of the Elements (Wiley, New York 1974)
2. K. Vainshtein: Sovremennaya kristallografiya. T.I. Simmetriya kristallov. Metody strukturnoi kristallografiya (Nauka, Moscow 1979) [English transl.: Modern Crystallography I. Symmetry of Crystals, Methods of Structural Crystallography, Springer Ser. Solid-State Sci., Vo1.15 (Springer, Berlin, Heidelberg 1981)
3. B.K. Vainshtein: Fundamentals of Crystals, Modern Crystallography 1 (Springer, Berlin, Heidelberg 1994)
4. R. Sinclair, G. Thomas: J. Appl. Crystallogr. 8,206 (1975)
5. D.W.J. Cruickshank: 2nd Europ. Crystallographic Meeting, Keszthely, Hungary (1974) Abstracts