Sudoku Extreme 16x16 - Hardest Sudoku Puzzles for Experts - 80 Frightening Sudoku Puzzles - Fifth EditionPatrick Mueller, Nicolae Denis, Extreme Puzzles · First published 2022Open the Tome
Sudoku Extreme 16x16 - Hardest Sudoku Puzzles for Experts - 80 Out of This World Sudoku Puzzles - Eight EditionDorothe Art, Nicolae Denis, Extreme Puzzles · First published 2022Open the Tome
Sudoku Extreme 16x16 - Hardest Sudoku Puzzles for Experts - 80 Unearthly Sudoku Puzzles - Seventh EditionNicolae Denis, Stefan Keller, Extreme Puzzles · First published 2022Open the Tome
Mega Sudoku Challenge for Kids : 200 Puzzles from Easy to HardExtreme Puzzles · First published 2020Open the Tome
