Samurai Sudoku  (English, Paperback, Conceptis Puzzles)

This popular, even more challenging variant of sudoku is for true puzzle warriors, each consisting of five grids arranged with overlapping corners. While regular sudoku-solving techniques provide the starting point, this game's more complicated because the overlapping areas belong to two different grids and must comply with both rules simultaneously, changing the puzzle's underlying logic...and making these sudokus more fun for the serious fan.