20/04/2023
New puzzle book published! This time, we've put together a nice Sudoku-X collection. There's 7 difficulty levels so you can start easy and work your way up!
https://www.amazon.com/Sudoku-X-Adventure-Vol-Puzzles-Extreme/dp/B0C1JB5KP3
Sudoku-X Adventure Vol. 1: 420 Sudoku X Puzzles Very Easy to Extreme!