That's a bit curvy, but it's only along one axis. Or plane. Or whatever I was blathering about.
Mars wrote:You probably want do a bit extra than just laying flat books on top. It would probably be better if you put something on top of the curve to promote pushing it back in.
Whatever you try, leave it pressed under the weights for at least a week.
I wouldn't try using a steam iron until pressure alone stopped working. Heck, try manual bending and rolling the book with your hands first.