_:vb50818598 . _:vb50818598 . _:vb50818597 "Priscilla Walmsley" . _:vb50818597 . . _:vb50818596 . _:vb50818597 . . "Requirements for XML Schema 1.1" . _:vb50818596 . _:vb50818595 . . . _:vb50818595 . _:vb50818596 "Ashok Malhotra" . _:vb50818598 . _:vb50818595 "Charles Campbell" . "2003-01-21" .