Department of Mathematics, National Taiwan UniversityChuang, C.-L.C.-L.ChuangTSIU-KWEN LEE2018-09-102018-09-102005http://www.scopus.com/inward/record.url?eid=2-s2.0-17444382316&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/314031application/pdfapplication/pdfjournal article10.1016/j.jalgebra.2005.02.0102-s2.0-17444382316WOS:000228963500007