Challenging Sudoku Eight Logic Puzzles (Vol 1) 
 Chapter 5: Sixteen Challenging (DiffLev 13) Sudoku-8-X Puzzles (numbers 31-46) 
 
-  Step-by-step instructions for solving  Puzzle 31, (46/64)   Diff: 13/3.7221.1343.3773
 -  Step-by-step instructions for solving  Puzzle 32, (47/64)   Diff: 13/3.3112.3367.5544
 -  Step-by-step instructions for solving  Puzzle 33, (47/64)   Diff: 13/3.2225.3346.5552
 -  Step-by-step instructions for solving  Puzzle 34, (48/64)   Diff: 13/A.2234.4235.4765
 -  Step-by-step instructions for solving  Puzzle 35, (48/64)   Diff: 13/A.1222.3335.8891
 -  Step-by-step instructions for solving  Puzzle 36, (48/64)   Diff: 13/5.51A1.1224.6991
 -  Step-by-step instructions for solving  Puzzle 37, (48/64)   Diff: 13/5.3121.3244.5963
 -  Step-by-step instructions for solving  Puzzle 38, (48/64)   Diff: 13/3.231A.A346.5676
 -  Step-by-step instructions for solving  Puzzle 39, (48/64)   Diff: 13/2.1243.4644.3483
 -  Step-by-step instructions for solving  Puzzle 40, (49/64)   Diff: 13/7.6325.3332.3363
 -  Step-by-step instructions for solving  Puzzle 41, (49/64)   Diff: 13/5.7541.1245.4344
 -  Step-by-step instructions for solving  Puzzle 42, (49/64)   Diff: 13/5.4431.2341.2497
 -  Step-by-step instructions for solving  Puzzle 43, (49/64)   Diff: 13/4.4242.2125.9941
 -  Step-by-step instructions for solving  Puzzle 44, (50/64)   Diff: 13/3.4112.3337.7745
 -  Step-by-step instructions for solving  Puzzle 45, (50/64)   Diff: 13/3.2422.4445.7841
 -  Step-by-step instructions for solving  Puzzle 46, (50/64)   Diff: 13/1.AAA1.3555.5975