Eraser-Free Sudoku, Volume A

The book contains 90 big Sudpku puzzles, two per page -- 40 Easy's, 40 Medium's, and 10 Hard's -- and we call them "Eraser-Free" because every vacant square has a "ScratchPad" at the bottom for writing in the "possibles." In other words, in this Sudoku book, erasing is totally optional. You can even solve in pen!