It's slightly inaccurate in that it doesn't mention any other routing protocol than BGP. BGP is used between Autonomous Systems, but within ASs usually other routing protocols are used.
BGP is the routing protocol on the internet, and it's a fairly common one to see inside enterprise networks as well - iBGP is for routing inside an AS. Describing OSPF, IS-IS, etc would have just made things a little more complicated without adding anything.
Inside the major network to your cable headend or similar: OSPF or IS-IS or something else - in the largest ISPs, a combination of iBGP to get things to right area and then OSPF, IS-IS or EIGRP in medium areas.
Inside your house: almost always static routes, no protocol for exchanging reachability info.
You should consider reading Kurose/Ross: http://eclass.uth.gr/eclass/modules/document/file.php/INFS13...