Cita APA (7a ed.)

Cioara, J., & Valentine, M. (2011). CCNA Voice 640-461 official cert guide (2nd ed.). Cisco Press.

Cita Chicago Style (17a ed.)

Cioara, Jeremy, y Michael Valentine. CCNA Voice 640-461 Official Cert Guide. 2nd ed. [Indianapolis, Ind.]: Cisco Press, 2011.

Cita MLA (8a ed.)

Cioara, Jeremy, y Michael Valentine. CCNA Voice 640-461 Official Cert Guide. 2nd ed. Cisco Press, 2011.