Books by Richard A. Deal
CCNA Cisco certified network associate security study guide (Exam 640-553)
Cisco ASA configuration
CCNA Cisco Certified Network A
CCNA Cisco Certified Network Associate Study Guide (Exam 640-802)
CCNP BCMSN Exam Cram 2 (642-811)
MCNS
MCNS exam cram
CCNP Cisco LAN switch configuration
CCNP Cisco LAN Switch Configuration Exam Cram: Exam