Hi Wissam,

Nice to see you back and congrats on passing your CCIE written exam :)

Here are some excellent Unity books;

Cisco Unity Deployment and Solutions Guide

Cisco Unity Fundamentals

Configuring CallManager and Unity: A Step-by-Step Guide

Here is the link to Cisco Press;

https://ciscobookstore.informit.com/cisco_press/index.asp?n=5064FF2D-3619-4FE4-B990-959DAB1FA484&b=Book

As far as IPCC, there are no Cisco Press books out there yet. Have a look at this great post from fellow NetPro Chris Deren, he has listed some really good Cisco IPCC docs;

http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Unified%20Communications%20and%20Video&topic=IP%20Telephony&CommCmd=MB%3Fcmd%3Dpass_through%26location%3Doutline%40%5E1%40%40.1ddd1e53/0#selected_message

Hope this helps! And best of luck.

Rob