Difficult Sudoku Twelve Logic Puzzles (Vol 1)
Chapter 22: Two Difficult (DiffLev 9) Considerably Puzzles (numbers 123-124)
- Step-by-step instructions for solving Puzzle 123, (85/144) Diff: 9/9.7899.9951
- Step-by-step instructions for solving Puzzle 124, (91/144) Diff: 9/9.9687.9994