The pop-up artist behind such winning abstract art books as One Red Dot, Blue 2, and 600 Black Spots (as well as the delightfully silly Bugs in a Box books), David A. Carter offers his newest book of paper sculptures in the form of a hunt for a yellow square. You might not see it until a square hole aligns with a yellow patch of color, or a wheel spins it into place, or you flex the book in just the right way, but finding it is only part of the fun, as the search takes you through wrestling noodles, a trapeze, a vortex of swirligigs, and over the moon with a very abstracted cow.