APA (7th ed.) Citation

Cisco Systems, Inc, Sauer, T. A., & Wallace, K. C. (2011). CCNP voice CVoice 642-437 quick reference (3rd ed.). Cisco Press.

Chicago Style (17th ed.) Citation

Cisco Systems, Inc, Toby Author Sauer, and Kevin Contributor Wallace. CCNP Voice CVoice 642-437 Quick Reference. 3rd ed. [Place of publication not identified]: Cisco Press, 2011.

MLA (9th ed.) Citation

Cisco Systems, Inc, et al. CCNP Voice CVoice 642-437 Quick Reference. 3rd ed. Cisco Press, 2011.