Samurai is for anyone who wants to enjoy extra-challenging extended-length Su Dokus. If you regularly relish number puzzles but they are solved within minutes, you might prefer the extra exertion involved for Samurai. With its larger and more complex grid, Samurai Su Doku will have you glued to your chair mentally toiling for hours.
Samurai Su Doku
HarperCollins Publishers Limited
100 Puzzles Including Super Difficult