Medium Sudoku Five Logic Puzzles (Vol 1) 
 Chapter 4: Twelve Medium (DiffLev 6) Sudoku-5 Puzzles (numbers 13-24) 
 
-  Step-by-step instructions for solving  Puzzle 13, (17/25)   Diff: 6/33.2333
 -  Step-by-step instructions for solving  Puzzle 14, (19/25)   Diff: 6/42.2551
 -  Step-by-step instructions for solving  Puzzle 15, (19/25)   Diff: 6/32.3344
 -  Step-by-step instructions for solving  Puzzle 16, (19/25)   Diff: 6/23.3632
 -  Step-by-step instructions for solving  Puzzle 17, (19/25)   Diff: 6/22.3444
 -  Step-by-step instructions for solving  Puzzle 18, (19/25)   Diff: 6/21.3571
 -  Step-by-step instructions for solving  Puzzle 19, (20/25)   Diff: 6/53.2442
 -  Step-by-step instructions for solving  Puzzle 20, (20/25)   Diff: 6/42.4451
 -  Step-by-step instructions for solving  Puzzle 21, (20/25)   Diff: 6/32.3444
 -  Step-by-step instructions for solving  Puzzle 22, (20/25)   Diff: 6/25.3235
 -  Step-by-step instructions for solving  Puzzle 23, (20/25)   Diff: 6/13.5353
 -  Step-by-step instructions for solving  Puzzle 24, (21/25)   Diff: 6/34.4343