Challenging Sudoku Twelve Logic Puzzles (Vol 1)
Chapter 47: Two Challenging (DiffLev 15-17) Supernotably Puzzles (numbers 173-174)
- Step-by-step instructions for solving Puzzle 173, (91/144) Diff: 15/836.4353.2699.9983
- Step-by-step instructions for solving Puzzle 174, (87/144) Diff: 17/9.4331.2311.4954.7993