The Help our good man Capo thread

I need sources for an essay about the develpment and use of heavy infantry and heavy infantry tactics, the rough draft due on the 15th. I know everything i need to know but they need at least 5 sources and no more than half of them can be off the internet (but I can do personal interviews for the rest) so some people please post links and anyone I can ask 1 question to through AIM can you please post here? thanks dudes I will love you forever in a family type way.
-Capo