Your Daily Sudoku Extreme Puzzle Book Is A Brand New Collection Of 366 Very Hard Sudoku 9x9 Grids For The 2020 Leap Year***Great Gift For Family, Friends or Colleagues*** ALWAYS in Stock on Amazon 366 "Exteme" Sudoku puzzles for the Highly Advanced Puzzler. Includes a special "Introduction to Sudoku" section. A brand new sudoku puzzle for every day of the leap year. A handy 8.5" x 11" size book. Plenty of white space for number scribbling. Ideal for exercising your brain cells. Includes full solutions for every puzzle at the back of the book. All the puzzles in this book are specially designed for advanced puzzlers and do not appear in any of our other PuzzlerBooks.com titles.