Difficult Sudoku Twelve Logic Puzzles (Vol 1)
Chapter 51: Two Difficult (DiffLev 11-13) Unimprovable Puzzles (numbers 181-182)
- Step-by-step instructions for solving Puzzle 181, (79/144) Diff: 11/995.5245.9747
- Step-by-step instructions for solving Puzzle 182, (99/144) Diff: 13/6.2546.9989.9992