Sudoku 200: Medium Puzzles for the Advanced Beginner by Mason Bencomo, Paperback | Barnes & Noble®
The Art of Puzzles — LiveJournal
The Must Have 2014 Sudoku Puzzle Book: 365 Sudoku Puzzles. A puzzle a day to challenge you every day of the year. 5 difficulty levels. by Jonathan Bloom, Paperback | Barnes & Noble®