200 fun Medium to Hard sudoku puzzles for brain gym. Great Christmas gift for sudoku lovers. - LOTS of puzzles: 100 Medium, 100 Hard with the solutions at the back. - 2 Big puzzles on each page gives you space to note. - Easy to tear out to grab and go. - Large print on white paper. - Size 8.5x11 similar A4 size but shorter in height. - So many volume versions for your choices, for each volume the game inside are not duplicate you can buy for yourself and for the Christmas gift as much as for your need!! - Or can get more than one book in the same vol. and arrange a friend challenge for Christmas Party. Let's start to enjoy this Sudoku simple for your brain gym and have fun.!!