200+ Sudoku Hard To Extreme: A Unique Collection Of 200 Extremely Hard Sudoku Puzzles Book Plus Techniques And Solutions...Crack The Hardest Sudoku Puzzles A.K.A The Extreme SUDOKU Challenge! Vol.1

by Jay Johnson Paperback details (USA). ISBN: 978-1-0995-9540-0 ISBN-10: 1-0995-9540-1 Independently published · May 2019