Kings of Sudoku - 500+ Sudoku Puzzles - Easy, Medium, HardJack Rubin brings you 500+ Sudoku that keep your mind vital and further strengthen your cognitive skillsYou will discover the following in this book: 504 captivating sudoku puzzlesThis book is printed in a handy size making it very practical to take with you to the beach, pool or vacationEvery puzzle has surely only one solution