JOURNAL OF MATERIALS RESEARCH, vol. 8, no. 12, page. 3184 - 3191, 1993-12
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, vol. 76, no. 6, page. 1482 - 1490, 1993-06
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, vol. 76, no. 2, page. 549 - 552, 1993-02