Killer Sudoku X 200 Puzzles Author:Gareth Moore Featuring a huge number of Killer Sudoku X puzzles, all carefully sorted into order of increasing difficulty, this unique collection of 200 puzzles is full of attractively-designed challenges from best-selling puzzle author Dr Gareth Moore, author of many international books. Killer Sudoku X builds on regular Sudoku by adding both extra diagonal... more » constraints and dashed-line cages which must sum to a given value - even the 'easy' puzzles in this book are pretty tricky! Printed on large, top-quality paper ideal for solving on, the 200 Killer Sudoku X puzzles vary in difficulty from easy to hard so whatever your preference or experience you'll always find a puzzle here to suit you.« less