BULLETIN OF THE KOREAN CHEMICAL SOCIETY, vol. 12, no. 6, page. 712 - 714, 1991-12-20
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, no. 9, page. 2270 - 2272, 1991-09
JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, no. 5, page. 326 - 327, 1991-03-01