[OSL | CCIE_Security] Recommended reading for advanced IOS firewall features, ZBF ect.?

[Simon Baumann]

Hi,
I wonder if there are any good book out covering the advanced fetures  
of the IOS firewall, ZBF and such stuff? I read great book about  
IPSec, AAA, ASA and so on.
But I couldn't find books for those topics. The Cisco Doc itself is  
available, sure....

Cheers
Simon