1. http://www.iwar.org.uk/comsec/resources/standards/germany/itbpm/s/s5013.htm
2. Roberts, Dr. Lawrence G. (May 1995). "The ARPANET & Computer Networks". Archived from the original on 24 March 2016. Retrieved 13 April 2016. Then in June 1966, Davies wrote a second internal paper, "Proposal for a Digital Communication Network" In which he coined the word packet,- a small sub part of the message the user wants to send, and also introduced the concept of an "Interface computer" to sit between the user equipment and the packet network.”
3. Davies, Shanks, Heart, Barker, Despres, Detwiler and Riml, "Report of Subgroup 1 on Communication System", INWG Note No. 1.
4. Vinton Cerf, Robert Kahn, "A Protocol for Packet Network Intercommunication", IEEE Transactions on Communications, Volume 22, Issue 5, May 1974, pp. 637 - 648.
5. David Boggs, John Shoch, Edward Taft, Robert Metcalfe, "Pup: An Internetwork Architecture" Archived 2008-09-11 at the Wayback Machine, IEEE Transactions on Communications, Volume 28, Issue 4, April 1980, pp. 612- 624.