PHYSICAL REVIEW B, vol. 56, no. 8, page. 4825 - 4829, 1997-08-15
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 31, no. SUP.2, page. S171 - S175, 1997-08
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 30, no. 2, page. 214 - 220, 1997-04
JOURNAL OF APPLIED PHYSICS, vol. 81, no. 5, page. 2454 - 2456, 1997-03-01
PHYSICS LETTERS A, vol. 226, no. 1-2, page. 17 - 21, 1997-02-10
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 30, no. 1, page. 70 - 73, 1997-02