Big Book Sudoku Jigsaw - 500 Hard to Master Puzzles 9x9 (Volume 14)

Sudoku Jigsaw (also known as "Irregular", "Nonomino" or "Geometric Sudoku") is a logic-based, combinatorial number-placement puzzle. Jigsaw Sudokus are very similar to regular Sudoku puzzles.
Regular 9x9 Sudoku that row and column rules apply, but instead of a 3x3 grid they are nine Jigsaw shapes. The puzzle books series contain:
- 250 Hard Puzzles
- 250 Master Puzzles
- Handy 6 x 9 inch Book Layout
- 6 Puzzles per Page
- Ideal for Experts The book is for those who like logic and math problems. Decide, developing and improving.