THIN SOLID FILMS, vol. 447, page. 443 - 448, 2004-01-30
SOLID STATE COMMUNICATIONS, vol. 127, no. 7, page. 469 - 473, 2003-08
SOLID STATE COMMUNICATIONS, vol. 127, no. 9-10, page. 645 - 648, 2003-09
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 42, no. 6, page. 783 - 786, 2003-06