Medium Sudoku Five Logic Puzzles (Vol 1) 
 Chapter 17: Twelve Medium (DiffLev 7) Sudoku-5C Puzzles (numbers 169-180) 
 
-  Step-by-step instructions for solving  Puzzle 169, (18/25)   Diff: 7/522.1242
 -  Step-by-step instructions for solving  Puzzle 170, (20/25)   Diff: 7/522.2342
 -  Step-by-step instructions for solving  Puzzle 171, (20/25)   Diff: 7/522.2342
 -  Step-by-step instructions for solving  Puzzle 172, (20/25)   Diff: 7/421.2434
 -  Step-by-step instructions for solving  Puzzle 173, (20/25)   Diff: 7/333.4241
 -  Step-by-step instructions for solving  Puzzle 174, (20/25)   Diff: 7/332.1245
 -  Step-by-step instructions for solving  Puzzle 175, (20/25)   Diff: 7/233.3342
 -  Step-by-step instructions for solving  Puzzle 176, (20/25)   Diff: 7/222.3551
 -  Step-by-step instructions for solving  Puzzle 177, (20/25)   Diff: 7/222.3533
 -  Step-by-step instructions for solving  Puzzle 178, (20/25)   Diff: 7/135.2351
 -  Step-by-step instructions for solving  Puzzle 179, (21/25)   Diff: 7/433.2342
 -  Step-by-step instructions for solving  Puzzle 180, (21/25)   Diff: 7/113.2365