1. Adams, C., Cain, P., Pinkas, D., Zuccherato, R.: – RFC 3161 Internet X.509 Public Key Infrastructure Time Stamp Protocol, TSP (2001),
http://www.ietf.org/rfc/rfc3161
2. Baldwin, A., Shiu, S., Casassa Mont, M.: Trust Services: A Framework for Service based Solutions. In: Proceedings of the 26th IEEE COMPSAC (2002)
3. Lecture Notes in Computer Science;A. Baldwin,2003
4. Lecture Notes in Computer Science;A. Baldwin,2003
5. Bayer, D., Haber, S.A., Stornetta, W.S.: Improving the efficiency and reliability of digital time-stamping. In: Sequences 1991: Methods in Communication Security and Computer Science, pp. 329–334. Springer, Heidelberg (1992)