The Times Su Doku Book 6 : 150 Challenging Puzzles from the Times

To feed the nation's addiction further, here is the sixth installment of The Times Su Doku puzzles. Now with even more puzzles for the hardened Su Doku addict, The Times Su Doku Book 6 contains 150 puzzles, ranging from mercifully Mild to the uber challenging Super fiendish.
40 Mild puzzles
50 Difficult puzzles
50 Fiendish puzzles
10 Super fiendish puzzles
With brand new puzzle suppliers, market-leader The Times offers a whole new collection of numerical conundrums for your brain to wr