300 Hard and Very Hard Sudoku puzzles, with solutions. Every puzzle requires tough Sudoku solving strategies (or you can always use up your erasers with the trial and error method). Bonus: Includes 4 "Infuriating" level puzzles to challenge the best solvers around. Two puzzles per page in this 5"x8" book means there is enough room to make notes, while it still fits in your coat pocket or purse.