Mills, David L. (1976). "An overview of the distributed computer network". Proceedings of the June 7-10, 1976, national computer conference and exposition on - AFIPS '76. pp. 523–531. doi:10.1145/1499799.1499874. S2CID13375745.
Mills, David L. (2010). "Technical History of NTP". Computer Network Time Synchronization: the Network Time Protocol on Earth and in Space (2nd ed.). CRC Press. pp. 377–396. doi:10.1201/b10282-20 (inactive 12 July 2025). ISBN978-1-4398-1463-5.{{cite book}}: CS1 maint: DOI inactive as of July 2025 (link)
Mills, David L. (1976). "An overview of the distributed computer network". Proceedings of the June 7-10, 1976, national computer conference and exposition on - AFIPS '76. pp. 523–531. doi:10.1145/1499799.1499874. S2CID13375745.