Find others sudoku related sites bellow. A single matter to be verified before beginning a puzzle, assure yourself that the site proposes real Sudoku, that means there must be one and only one solution. Should the opposite occur, you will look for a long time for a logical solution which does not exist. This happens to me and after several hours, I guaranteed this is particularly infuriating!
I created some puzzles particularly difficult. Diabolical puzzles require advanced strategies to be resolved. If you are ready to unstitch it to find the solution, I invite you to consult this page.