Cisco 1900 Series Integrated Services Routers - Cisco
Gns3 Supported Routers IOS list Devices can be used on GNS - W7cloud
Hardware Architecture of the Cisco 7500 Router - Inside Cisco IOS Software Architecture (CCIE Professional Development) [Book]
What is Cisco IOS and What is the difference between Cisco iOS and bootstrap version
Cisco Router and IOS How To's Archives - CellStream, Inc.
Understanding Cisco IOS - Tech-FAQ
Cisco IOS XRv Router Installation and Configuration Guide - Mapping the Cisco IOS XRv Router Network Interfaces to the VM Network Interfaces [Cisco IOS XRv Software] - Cisco Systems