I have a D.O.D. sticker on the windshield of my car to get on base and such, I will have to replace it soon with a new one and Flatfoot told me that using a scraper of sorts and maybe some Goo Gone (or whatever) might help get it off without damaging the surface. However, yours is on the surface of a book, something far less scrapable than my windshield. I have an act for peeling stickers off without leaving sticky crap behind, but that doesn't do you so well, does it? Maybe peel it off and use Goo Gone for the after sticky mess. Not too sure of a good solution for this.
Edit/Add: I didn't realize you had already found a solution. Boo! I suck, but it's nice to know Goo Gone works. 😎