Medium Sudoku Twelve Logic Puzzles (Vol 1) 
 Chapter 3: Twelve Medium (DiffLev 5-6) Sudoku-12 Puzzles (numbers 1-12) 
 
-  Step-by-step instructions for solving  Puzzle 1, (64/144)   Diff: 5/9.9942
 -  Step-by-step instructions for solving  Puzzle 2, (69/144)   Diff: 5/9.9951
 -  Step-by-step instructions for solving  Puzzle 3, (70/144)   Diff: 5/9.9991
 -  Step-by-step instructions for solving  Puzzle 4, (75/144)   Diff: 5/9.9991
 -  Step-by-step instructions for solving  Puzzle 5, (75/144)   Diff: 5/9.9991
 -  Step-by-step instructions for solving  Puzzle 6, (59/144)   Diff: 6/99.7641
 -  Step-by-step instructions for solving  Puzzle 7, (66/144)   Diff: 6/99.9992
 -  Step-by-step instructions for solving  Puzzle 8, (68/144)   Diff: 6/99.9764
 -  Step-by-step instructions for solving  Puzzle 9, (69/144)   Diff: 6/99.9993
 -  Step-by-step instructions for solving  Puzzle 10, (72/144)   Diff: 6/99.9932
 -  Step-by-step instructions for solving  Puzzle 11, (77/144)   Diff: 6/99.9994
 -  Step-by-step instructions for solving  Puzzle 12, (77/144)   Diff: 6/99.9952