JOURNAL OF NON-CRYSTALLINE SOLIDS, vol. 353, no. 16-17, page. 1676 - 1680, 2007-06-01
JOURNAL OF NON-CRYSTALLINE SOLIDS, vol. 353, no. 13-15, page. 1251 - 1254, 2007-05-15
JOURNAL OF MATERIALS RESEARCH, vol. 21, no. 9, page. 2323 - 2330, 2006-09