4[1]ISO/IEC 9594-1/ITU-T Recommendation X.500.Information Tech-nology-Open Systems Interconnection-The Directory:Overview of concepts.Models and Services,ITU,1993
5[2]ISO/IEC 9594-8/ITU-T Recommendation X.509.Information Tech-nology-Open Systems Interconnection-The Directory:Authentication Framework.ITU,1997
6[3]ISO/IEC 9594-5/ITU-T Recommendation X.519.Information Tech-nology-Open Systems Interconnection-The Directory:Protocol specifi-cations.ITU,1993
