Sudoku Collection : 200 Very Hard Windoku Sudoku Puzzles 9X9

Sudoku may contain additional four regions 3 x 3. It is called Windoku.

• • Author: Alena Gurin
• • Publisher: Independently Published
• • Publication Date: Aug 28, 2019
• • Number of Pages: 122 pages
• • Language: English
• • Binding: Paperback
• • ISBN-10: 1689145234
• • ISBN-13: 9781689145237