Yu, C.-F.C.-F.YuJENG-DAW YU2018-09-102018-09-102009http://www.scopus.com/inward/record.url?eid=2-s2.0-70349810903&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/347064application/pdf198556 bytesapplication/pdfjournal article10.1016/j.jalgebra.2009.08.0082-s2.0-70349810903WOS:000270920000015