Challenging Sudoku Twelve Logic Puzzles (Vol 1)
Chapter 30: Two Challenging (DiffLev 20) Headstrongly Puzzles (numbers 139-140)
- Step-by-step instructions for solving Puzzle 139, (89/144) Diff: 20/9231.1AAA.1356.4476.9794
- Step-by-step instructions for solving Puzzle 140, (90/144) Diff: 20/9574.5431.C142.1333.9973