Hyper Sudoku X ●●●● : 100 Hard Puzzles

By Peter Ritmeester

The rules: insert the digits 1-9 just once in each a) row, b) column, c) bold outlined area, d) gray area and e) both long diagonals. See Ritmeester's author page for his 18 other books. Peter Ritmeester is the inventor of the Hyper Sudoku , where four gray regions also contain 1-9. For more than a decade he has published these Hypers in The International New York Times and many other newspapers worldwide. The four gray regions provide for some nice extra logic and the information you are looking for is hidden in four more regions. In this book there is yet another twist: the two long diagonals also have to contain 1-9. Ritmeester, owner of PZZL.com, created the puzzles for all sudoku books presented by Will Shortz, with average reviews of 4.5 stars.

• Format: Paperback
• Language: English
• ISBN: 1687126224
• ISBN13: 9781687126221
• Release Date: August 2019
• Publisher: Independently published
• Length: 128 Pages
• Weight: 0.39 lbs.
• Dimensions: 7.0" x 0.3" x 5.0"