JOURNAL OF THE AMERICAN CERAMIC SOCIETY, vol. 81, no. 10, page. 2586 - 2596, 1998-10
JOURNAL OF MATERIALS RESEARCH, vol. 12, no. 6, page. 1614 - 1624, 1997-06
JOURNAL OF MATERIALS RESEARCH, vol. 10, no. 12, page. 3185 - 3193, 1995-12