1. Bertinotti, F., Giacomello, G., Liquori, A. M.: Acta Cryst. 7 (1954) 808.
2. Bettman, M., Hughes, E. W.: Am. Cryst. Assoc., Programm and Abstracts, April 1954, p. 15.
3. Boyd, H.C., Edward, P.B.M., Goodwin, T.H., Hicks, D., MacFarlane, J., MacNaughton, L.: Acta Cryst. 7 (1954) 142.
4. Brown, C. J.: Acta Cryst. 7 (1954) 92.
5. Brown, C. J.: Acta Cryst. 7 (1954) 97.