F*ck! These Sudoku Puzzles are Hard!: Difficult Sudoku Puzzle Books for Adults - Large Print Hard Sudoku Puzzle Books - Answer Keys Included, Paperback/Super Brain Puzzles

Sudoku Large Print Puzzle Book for Adults: 200 Hard & Very Difficult Puzzles, Paperback/Kat Andrews

Sudoku Hard Puzzle Book: Extremely Difficult Challenge Brain Games for Expert Adults Sudoku Killer, Large Print, Devil Sudoku Killer V.1, Paperback/James D. Glover

Sudoku Large Print Puzzle Book for Adults: 100 Puzzles - Easy, Medium, Hard and Very Difficult, Paperback/Kat Andrews

Hard Sudoku Large Print: suduko puzzle books for adults difficult - Full Page HARD SUDOKU Maths Book to Challenge Your Brain - Sudoku in Very L, Paperback/Sophia Parkes