APPLIED PHYSICS LETTERS, vol. 78, no. 24, page. 3773 - 3775, 2001-06-11
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, vol. 40, no. 3A, page. 1188 - 1193, 2001-03
MRS INTERNET JOURNAL OF NITRIDE SEMICONDUCTOR RESEARCH, vol. 6, no. 4, page. 1 - 7, 2001-01