The books Sedayne mentioned aren't very old and are still in copyright. Second-hand copies aren't difficult to find; even nowadays, worthwhile things still must sometimes be bought with money (though Amazon doesn't necessarily offer the lowest prices). Sedayne certainly understood your question, but answered with tact.

Though I describe The White Goddess as 'worthwhile', I mean that it's a fascinating -though in places quite demanding- read. It's a curious mix of genuine scholarship and complete fantasy, and many readers are likely to have difficulty telling where the one ends and the other begins, so anyone trying to base some sort of belief system on it runs the risk of making themselves look ridiculous. Nevertheless, anybody interested in poetic myth should read it.