Using Whois - American Registry for Internet Numbers
Tracking user's IP Autonomous System Number and Organization details to prevent the spam - David Vallejo
Configuring BGP. Planning to Deploy BGP Prior to deploying a BGP routing solution, the following should be considered: – IP addressing plan – Network. - ppt download
Autonomous System Originations (Origin AS) - American Registry for Internet Numbers
Autonomous System — Wikipédia
Overview of BGP ASN (Autonomous System Numbers) in Networks