Ultimate Sudoku Challenge

Confident solvers who think they've got Sudoku down cold will have to think again, because these are absolutely the most fiendishly difficult, devilishly baffling Sudokus ever devised...and the biggest, too. Created by hand in Japan--from Nikoli, the company responsible for the puzzles' popularity in that country--the collection includes megasudokus on a 25 x 25 grid, designed to give even the sharpest minds a workout. True to its title, it's the ultimate challenge, and one that millions of Sudoku-obsessed fans will find irresistible. And for total newcomers brave enough to high-dive in at the deep end, there's a quick tutorial to get them started.Sterling Publishing is the author of 'Ultimate Sudoku Challenge ', published 2005 under ISBN 9781402736490 and ISBN 1402736495.