Will Shortz Presents Hot Sudoku: 200 Very Hard PuzzlesPaperback, 31 August 2010

In Will Shortz Presents Hot Sudoku: 200 Very Hard Puzzles, the New York Times' crossword editor and NPR's puzzlemaster has crafted some mindbenders to test your will and skill with numbers.

Perfectly portable for when you're on the go, this collection will fuel your fire to solve equations with puzzles that are going to make you sweat.