100 Sudoku Pocket Puzzles - Easy to Hard Level: Pocket Sudoku Puzzle Books For Adults, Travel Sudoku, Sudoku 100, Sudoku Challenge For Adults, Sudoku Puzzle Books Easy to hard ( Activity Book
Compact Size SUDOKU Puzzle Book For Adults: Sudoku Pocket: Travel-Friendly Book with 160 Easy Sudoku Puzzles and Solutions for Beginners a book by Bridget Puzzle