JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 61, no. 12, page. 1986 - 1989, 2012-12
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 55, no. 6, page. 2460 - 2464, 2009-12
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 54, no. 2, page. 668 - 672, 2009-02
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 53, no. 6, page. 3671 - 3674, 2008-12