Windoku: Hyper Sudoku : 250 Medium to Hard Four-Box Sudoku Puzzles (Series #15) (Paperback) - Walmart.com
Hyper Sudoku Book 5 : 200 Hard Sudoku Variant Puzzles (Paperback) - Walmart.com
Hypersudoku - Sudopedia Mirror
Hyper Sudoku: 100 Challenging Puzzles by Isolvepuzzles | Goodreads
Hyper Sudoku 200 Normal to Hard Sudoku Variant Puzzles Book 4: Buy Hyper Sudoku 200 Normal to Hard Sudoku Variant Puzzles Book 4 by Press Creative Logic at Low Price in India | Flipkart.com