Sung-Taek Hur, Suk-Won Choi*, Manhwan Lee, J. Kor. Phys. Soc., 2011, 58, 392.
http://www.kps.or.kr/jkps/abstract_view.asp?articleuid=C3E1323E-5A74-42BA-9EF1-81C6CA5DBF2B&globalmenu=3&localmenu=10