Below few books i recommend to read :)
CCIE Routing and Switching v5.1 Foundations: Bridging the Gap Between CCNP and CCIE
Even if you are don't like R&S stuff better to know this book written by Narbik
Cisco ISE for BYOD and Secure Unified Access
Integrated Security Technologies and Solutions - Volume I
CCNP Security SISAS 300-208 Official Cert Guide
Designing for Cisco Internetwork Solutions (DESGN) Foundation Learning Guide
Designing for Cisco Network Service Architectures (ARCH) Foundation Learning Guide
Cisco Firepower 6.x with Firepower Threat Defense (FTD): Next Generation Firewall (NGFW)
Troubleshooting Cisco Nexus Switches and NX-OS
Deploying ACI: The complete guide to planning, configuring, and managing Application Centric Infrastructure
CCNA Data Center DCICN 200-150 Official Cert Guide
CCNA Data Center DCICT 200-155 Official Cert Guide