Variations on Intermediate Sudoku Logic Puzzles (Vol 1) 
 Chapter 36: Eight Difficult Sudoku-7D Puzzles (numbers 197-204) 
 
-  Step-by-step instructions for solving  Puzzle 197, (34/49)   Diff: 9/5.3232.3583
 -  Step-by-step instructions for solving  Puzzle 198, (37/49)   Diff: 11/433.3331.3662
 -  Step-by-step instructions for solving  Puzzle 199, (38/49)   Diff: 11/752.2314.4361
 -  Step-by-step instructions for solving  Puzzle 200, (38/49)   Diff: 11/522.2123.5763
 -  Step-by-step instructions for solving  Puzzle 201, (38/49)   Diff: 11/351.1126.6562
 -  Step-by-step instructions for solving  Puzzle 202, (39/49)   Diff: 11/434.2125.7542
 -  Step-by-step instructions for solving  Puzzle 203, (39/49)   Diff: 11/353.3223.4662
 -  Step-by-step instructions for solving  Puzzle 204, (36/49)   Diff: 12/221A.A221.3795