The classic anarcho-capitalist writings, beginning with Murray Rothbard and David Friedman
The great debates, including Nozick versus his critics, Roy Childs' critique of Ayn Rand, and Tyler Cowen vs. David Friedman (added bonus: Cowen and Sutter versus Caplan and Stringham)
The history of anarcho-capitalist thought, including Gustave de Molinari and Lysander Spooner
Historical case studies - Ireland, Iceland, and the not so wild, wild West
Most economists who invest the time to study the anarcho-capitalist literature ultimately aren't convinced. But I've yet to met an economist who made the investment who didn't end up taking it a lot more seriously than he expected.
Personally, my favorite short-cut to credibility on this "crazy" topic is to start with the "minimal" state, then point out all the ways that it could do even less. (See here, here, and here).