The New York Times' crossword editor and NPR's puzzlemaster invites you to try your hand and mind at solving some incredible brainteasers in Will Shortz Presents Ferocious Sudoku: 200 Hard Puzzles. Perfectly sized for traveling with big grids for easy solving, discover if you are tough enough to take on the challenge of this collection of 200 devilishly difficult sudoku puzzles! | Will Shortz Presents Ferocious Sudoku, Paperback | Indigo Chapters