Difficult Sudoku Twelve Logic Puzzles (Vol 1)

Chapter 49: Two Difficult (DiffLev 10-13) Turbomachine Puzzles (numbers 177-178)

• Step-by-step instructions for solving Puzzle 177, (81/144)   Diff: 10/99.6566.8785
• Step-by-step instructions for solving Puzzle 178, (94/144)   Diff: 13/5.7976.9779.6961