1. American National Standard Institute (ANSI). ANSI X9.95-2016 - Trusted Timestamp Management and Security (2016)
2. Adams, C., Cain, P., Pinkas, D., Zuccherato, R.: RFC 3161: Internet X. 509 Public Key Infrastructure Time-Stamp Protocol (TSP) (2001)
3. ISO/IEC 18014–1:2008. Information technology - Security techniques - Time-stamping services - part 1: Framework. Standard (2008)
4. ISO/IEC 18014–2:2009. Information technology - Security techniques - Time-stamping services - part 2: Mechanisms producing independent tokens. Standard (2009)
5. ISO/IEC 18014–3:2009. Information technology - Security techniques - Time-stamping services - part 3: Mechanisms producing linked tokens. Standard (2009)