Cita APA (7a ed.)

Wilkins, S., & Smith, F. H. (2011). CCNP security secure 642-637 official cert guide. Cisco Press.

Cita Chicago Style (17a ed.)

Wilkins, Sean, y Franklin H. Smith. CCNP Security Secure 642-637 Official Cert Guide. Indianapolis, Ind.: Cisco Press, 2011.

Cita MLA (8a ed.)

Wilkins, Sean, y Franklin H. Smith. CCNP Security Secure 642-637 Official Cert Guide. Cisco Press, 2011.