I've read some of his short stories and his book on writing, but never one of his novels. He's one of the fantasy writers who doesn't get all that much attention these days.
You can order this [used] on Amazon. It's is actually a compilation of several pieces on the character Harold Shea, but reads as if it were written as one novel. I just [reluctantly] gave my copy to an appreciative friend of my daughter (along with some other de Camp novels, the Krishna series, which I also recommend). We are moving and sacrifices had to be made. Sigh.