Cisco Networking Academy Program. (2003). Cisco Networking Academy Program: It essentials II, Network operating companion guide (First edition.). Editorial Cisco Press.

Cisco Networking Academy Program. Cisco Networking Academy Program: It Essentials II, Network Operating Companion Guide. First edition. Indianápolis: Editorial Cisco Press, 2003.

Cisco Networking Academy Program. Cisco Networking Academy Program: It Essentials II, Network Operating Companion Guide. First edition. Editorial Cisco Press, 2003.