I don't think you'll find a single source that provides authentic recipes for a wide variety of different ethnic foods. I think you'll need to find a good source for each type of food, unfortunately. The only book I have that I'd consider authentic is The Breath of a Wok, which covers a wide range of Chinese food. Maybe each ethnicity could use a question for "What's an authentic and comprehensive book for [type of food]?"
I use a line of cookbooks available in the US called Best Recipe which tends to be very good. They have an International Version which goes through many different types of food. It's a great book, but it's not particularly authentic. So if you're looking for breadth and good recipes, it's a good one. But I'm not sure it would suffice to cook for a native nor meet the standard set forth in the question.