Will Shortz Presents Treacherous Sudoku: Harder Puzzles

This book is for savvy sudoku solvers who are looking for puzzles that are harder than hard

Features:
200 fearsome puzzles
Edited by legendary New York Times crossword editor Will Shortz
Portable and affordable package

Also in the series:
-Will Shortz Presents Tough Sudoku
-Will Shortz Presents Terrifying Sudoku