1000+ Sudoku Puzzles for Adults: A Book With More Than 1000 Sudoku Puzzles from Easy to Hard for adults. Nova, Publishing XR
Amazing A-Z AlphaQuest Seek & Find Challenge Puzzle Book: Discover Over 2,500 Brilliantly Illustrated Objects! (Fox Chapel Publishing) 26 Puzzles with a Variety of Hidden Objects – Adult Activity Book Andrew Ruhren
My Best Mathematical and Logic Puzzles (Dover Recreational Math) (Dover Math Games & Puzzles) Gardner, Martin