::* <cite id=refNSA95>Thomas R. Johnson, ''American Cryptology during the Cold War: 1945-1989.'' [http://www.nsa.gov/public_info/_files/cryptologic_histories/cold_war_i.pdf Book I: The Struggle for Centralization 1945-1960], 1995</cite> | ::* <cite id=refNSA95>Thomas R. Johnson, ''American Cryptology during the Cold War: 1945-1989.'' [http://www.nsa.gov/public_info/_files/cryptologic_histories/cold_war_i.pdf Book I: The Struggle for Centralization 1945-1960], 1995</cite> |