But I mostly focused on fiction, and when I wrote non-fiction it was mostly short articles.
I did consider eventually writing actual non-fiction books, though, and did a lot of preliminary work on a planned history of pre-Comics Code horror comics, to be called Strange! Eerie! Terrifying!. But I never completed it; other people got there first and I decided it wasn't worth the effort. (Much of the research wound up in a long, oft-reprinted article, "The Other Guys.")
So as of now, I have only two books of non-fiction to my name:
Follow the links for more details.
That's it; here's your list of handy exits: