Wu, Kuen-PinKuen-PinWuRuan, Shanq-JangShanq-JangRuanTseng, Chih-KuangChih-KuangTsengLai, FeipeiFeipeiLai2009-02-272018-07-062009-02-272018-07-062001http://ntur.lib.ntu.edu.tw//handle/246246/142040en-USHierarchical Access Control Using the Secure Filterjournal article