Does anyone have a good resource for the terminology of book formats for old-school publishing? Specifically, I'm wondering what those double-feature pocket-sized pulp fiction novels were called. The kind that had two books back to back, but the text flipped in the middle, so each book could be read from the beginning with its own separate cover. I think they used to do this in the 20's and 30's. I saw some G-Man adventure stories in a museum in DC that were published like this. Any help would be appreciated. Thanks!
And yeah, Ace Double Novels. Fahim has links to pages that show the covers if you like.
