The Nastiest Sudoku Book Ever

Only diehards need apply These incredibly difficult sudoku are made to challenge even the most expert solver...and strain their brains to bursting. Each puzzle requires upper-level strategies that have been honed to perfection from regular practice. Designed by powerhouse sudoku creator Frank Longo, they'll have dedicated fans tearing their hair out-and loving every moment.
This is a bind-up of books 2, 3, and 4 our four-part Absolutely Nasty sudoku series.