Yun Bai Vijay Varadharajan Object Oriented Database with Authorization Policies. 229-250 2002 53 Fundam. Inform. 3-4 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=53&issue=3&spage=229 db/journals/fuin/fuin53.html#BaiV02