Paul Baran: Centralized, Decentralized and Distributed networks (1964)

Baran, P. (1964). On Distributed Communications, Memorandum RM-3420-PR. Santa Monica, Calif.: RAND Corporation. Available at: http://www.rand.org/content/dam/rand/pubs/research_memoranda/2006/RM3420.pdf (Accessed May 29, 2017).

Also: http://innovationprinciples.blogspot.co.uk/2013/06/scalable-innovation-figures-for-section_14.html