ISBN Hunt

In the quest for the truly obscure, I've looked for comprehensive checklists of Horror and Men's Adventure books with limited success - Vault of Evil has some good ones by publisher.  I've also flipped through most of the covers on BookScans, though that site ends with 1979.

I've started doing a deep dive on some of the more specialized publishers, one ISBN number at a time.  Publishers tend to buy ISBN numbers in blocks, as they get way cheaper in bulk.  Starting with the number range from ISFDB, I look up the ISBN numbers one at a time.  The last digit is a check number, which can be calculated here.  I then type the ISBN directly into the url as the product code for Amazon.  If anyone knows an easier way, I'd love to hear it.

There are lots of ISBN databases, but none are nearly as comprehensive as Amazon.  I double check Google if Amazon comes up empty, but if the 'zon doesn't have it, it rarely comes up anywhere else.  I take our information age for granted, but there are so many books with zero information.  Some have no cover and maybe a partial title and author, and I have to dig around for enough information to guess at a genre.

I hope to rectify some of that, and I'm grabbing some of the re-discovered horror novels as I go, provided they're cheap enough.  I'm only hitting up certain publishers: Zebra, Pinnacle, Leisure, Gold Eagle, Critic's Choice, etc, ones that only go through a couple hundred ISBN numbers a year.  Some of the larger houses easily go through thousands a year, and I'm not that crazy.