[3] Chen T T,Chao G Y.Canadian Mineralogist,1980,18:77.
[4] Peng C J.American Mineralogist,1955,40(9-10):853.
[5] Pechar F,Rykl D.Canadian Mineralogist,1983,21:693.
[6] Pechar F.Chemical Papers-Chemicke Zvesti (in Czech),1982,36:773.
[7] Dutta P K,Barco B D.Journal of Physical Chemistry,1985,89:1862.