The puzzles in this collection of treacherously difficult puzzles will stretch even the most advanced Su Doku enthusiast. You will need to use all of your best

This is Su Doku multiplied: every column, row and 3x3 box must contain the digits 1 to 9. Where the puzzles overlap, the rows and columns do not go beyond their

Welcome to the 9 Circles of Sudoku Hell! From Merciless to Maddening to Murderous, this is a book to challenge even the most seasoned Sudokuist. By the end of t

A collection of 200 previously unpublished Fiendish Su Doku puzzles. Perfect for the expert solver in need of a constant supply of ultra-difficult puzzles. Guar

A new collection of previously unpublished Fiendish Su Doku puzzles with the added bonus of 30 Super Fiendish puzzles. Perfect for the advanced solver in need o