Harder Sudoku puzzles on the way? › News in Science (ABC Science)
The Logical World of Puzzles: Rules of 'Alphabet Sudoku'
Cross+A :: Sudoku
Sudoku Alphabet: 100 traditional puzzles with a twist using letters of the alphabet. Keep your brain active with these highly addictive logic puzzles. Large print with solutions.: House, Lilac: 9781686584565: Amazon.com: Books