Jigsaw Sudoku Book: 200 Hard Jigsaw Sudoku Puzzles, Irregularly Shaped Sudoku, Sudoku Books for Adults: New | Books Unplugged
Jigsaw Sudoku Adult Puzzle Book: 1000 Medium to Very Hard Irregular Sudoku Puzzles (The Big Books of Logic Puzzles Series): Alzamili, Dr. Khalid: 9798515978716: Amazon.com: Books