Medium Sudoku Six Logic Puzzles (Vol 1) 
 Chapter 16: Twelve Medium (DiffLev 6) Sudoku-6up-UR-D Puzzles (numbers 157-168) 
 
-  Step-by-step instructions for solving  Puzzle 157, (24/36)   Diff: 6/46.4442
 -  Step-by-step instructions for solving  Puzzle 158, (24/36)   Diff: 6/43.3383
 -  Step-by-step instructions for solving  Puzzle 159, (25/36)   Diff: 6/94.4241
 -  Step-by-step instructions for solving  Puzzle 160, (25/36)   Diff: 6/83.3371
 -  Step-by-step instructions for solving  Puzzle 161, (26/36)   Diff: 6/44.6534
 -  Step-by-step instructions for solving  Puzzle 162, (27/36)   Diff: 6/68.5422
 -  Step-by-step instructions for solving  Puzzle 163, (27/36)   Diff: 6/66.5433
 -  Step-by-step instructions for solving  Puzzle 164, (27/36)   Diff: 6/63.3564
 -  Step-by-step instructions for solving  Puzzle 165, (27/36)   Diff: 6/34.5681
 -  Step-by-step instructions for solving  Puzzle 166, (28/36)   Diff: 6/43.3549
 -  Step-by-step instructions for solving  Puzzle 167, (28/36)   Diff: 6/33.6583
 -  Step-by-step instructions for solving  Puzzle 168, (29/36)   Diff: 6/46.3591