ISBN 1095091255 books & textbook
Extreme Sudoku Collection: The Hardest Sudoku Collection Ever Made With Diabolical Puzzles Not Suitable For Beginners (Test Your Sudoku Solving Skills With The Rest Of The World)
Independently published /2019-04-18 Paperback / 304 Pages
isbn-10: 1095091255 / isbn-13: 9781095091258
