APA (7th ed.) Citation

Beker, H. J., & Piper, F. C. (1985). Secure speech communications. Academic Press.

Chicago Style (17th ed.) Citation

Beker, Henry J., and F. C. Piper. Secure Speech Communications. London: Academic Press, 1985.

MLA (8th ed.) Citation

Beker, Henry J., and F. C. Piper. Secure Speech Communications. Academic Press, 1985.