100 Sudoku Puzzles

100 different Sudoku puzzles in different degrees of difficulty and sizes from 4x4 to 16x16. The puzzles may be freely distributed or used for publication. The rules for solving a Sudoku are simple: Each row, column and region must contain the numerals from 1 through 9 exactly once. The Puzzles are in Adobe PDF file format and have not to be installed. You can easily print and then work them out with pencil and paper.