Break-Through Su Doku: From Difficult to Fiendish
HarperCollins Publishers Limited, Mar 1, 2009 - 208 pages
With 100 puzzles and solutions ranging from difficult to fiendish, Wayne Gould offers commentaries to help you make the break-through transition to solve puzzles at 'fiendish' level. By revealing some of the more sophisticated solving concepts, puzzlers familiar with su doku will be able to successfully solve advanced puzzles.
In addition to an introduction and basic su doku solving techniques, there are also practise puzzles at the higher level where you can time yourself to discover whether you are slow, average or pro.