Difficult Sudoku Twelve Logic Puzzles (Vol 1)
Chapter 47: Two Difficult (DiffLev 12-14) Supernotably Puzzles (numbers 173-174)
- Step-by-step instructions for solving Puzzle 173, (89/144) Diff: 12/9779.6777.9861
- Step-by-step instructions for solving Puzzle 174, (98/144) Diff: 14/99.9946.4569.7353