1. Landolt-Börnstein, NS, Vol. II/15: Structure Data of Free Polyatomic Molecules. Berlin, Heidelberg, New York: Springer, 1987.
2. Wyckoff, R.W.G.: “Crystal Structures”, Vol. 1. New York: Wiley-Interscience, 1965.
3. Landolt-Börnstein, NS, Vol. III/7b1: Crystal Structure Data of Inorganic Compounds. Berlin, Heidelberg, New York: Springer, 1975.
4. Campbell, M.J., Liesegang, J., Riley, J.D., Jenkin, J.G.: J. Phys. C15 (1982) 2549.
5. Campbell, M.J., Liesegang, J., Riley, J.P., Leckey, R.C.G., Jenkin, J.G., Poole, R.T.: J. Electron. Spectrosc. Relat. Phenom. 15 (1979) 83.