Enter the Goodreads giveaway for a chance to win a copy of Infinite Sudoku, christmas edition. The book contains a collection of 2850 sudoku puzzles in various levels of difficulty. Each puzzle has a unique solution. All puzzles can be solved using logic, no guessing required.

The giveaway starts on December 18th and ends on December 26th.

Download for free the kindle version of “499 Quick Sudoku” on December 25th and December 26th.