Challenging Sudoku-by5 Logic Puzzles (Vol 1) 
 Chapter 3: Sixteen Challenging (DiffLev 15) Sudoku-by5 Puzzles (numbers 1-16) 
 
-  Step-by-step instructions for solving  Puzzle 1, (239/369)   Diff: 15/999.9997.9999.9991
 -  Step-by-step instructions for solving  Puzzle 2, (244/369)   Diff: 15/999.9999.994D.5451
 -  Step-by-step instructions for solving  Puzzle 3, (245/369)   Diff: 15/999.9997.8547.8663
 -  Step-by-step instructions for solving  Puzzle 4, (248/369)   Diff: 15/999.9999.9999.9862
 -  Step-by-step instructions for solving  Puzzle 5, (248/369)   Diff: 15/999.9999.9999.8572
 -  Step-by-step instructions for solving  Puzzle 6, (249/369)   Diff: 15/999.9999.9999.9932
 -  Step-by-step instructions for solving  Puzzle 7, (249/369)   Diff: 15/999.9999.9969.8884
 -  Step-by-step instructions for solving  Puzzle 8, (252/369)   Diff: 15/999.9999.9999.9552
 -  Step-by-step instructions for solving  Puzzle 9, (253/369)   Diff: 15/999.9999.9535.8343
 -  Step-by-step instructions for solving  Puzzle 10, (254/369)   Diff: 15/999.9999.9997.9762
 -  Step-by-step instructions for solving  Puzzle 11, (256/369)   Diff: 15/999.9999.9999.9994
 -  Step-by-step instructions for solving  Puzzle 12, (257/369)   Diff: 15/996.9999.9999.9994
 -  Step-by-step instructions for solving  Puzzle 13, (258/369)   Diff: 15/999.9999.9999.9742
 -  Step-by-step instructions for solving  Puzzle 14, (262/369)   Diff: 15/999.9999.9999.9994
 -  Step-by-step instructions for solving  Puzzle 15, (264/369)   Diff: 15/999.9999.9997.9953
 -  Step-by-step instructions for solving  Puzzle 16, (268/369)   Diff: 15/999.9999.9999.9992