Cita APA (7th ed.)

Hooper, H. (2012). CCNP security VPN 642-648 official cert guide. Cisco Press.

Cita Chicago (17th ed.)

Hooper, Howard. CCNP Security VPN 642-648 Official Cert Guide. Indianapolis, Ind: Cisco Press, 2012.

Cita MLA (9th ed.)

Hooper, Howard. CCNP Security VPN 642-648 Official Cert Guide. Cisco Press, 2012.