Churchhouse, R. F. (2002). Codes and ciphers: Julius Caesar, the Enigma, and the internet. Cambridge University Press.
Dyfyniad Arddull ChicagoChurchhouse, R. F. Codes and Ciphers: Julius Caesar, the Enigma, and the Internet. Cambridge ; New York: Cambridge University Press, 2002.
Dyfyniad MLAChurchhouse, R. F. Codes and Ciphers: Julius Caesar, the Enigma, and the Internet. Cambridge University Press, 2002.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.