http://appliedballisticsllc.com/products/books/

Litz has a number of books that might seem to overlap. Is there one over the others that is better, or a progression? I've taken a couple of long range classes and get the basics, but between time and my notes from class sucking, I start to lose much beyond those basics. Looking for something that I can reference and start to build a better 'model' in my head of what is going on. I've got some time over the Holidays to get some reading in.

Thanks