Variations on Intermediate Sudoku Logic Puzzles (Vol 1) 
 Chapter 40: Eight Medium Sudoku-8 Puzzles (numbers 221-228) 
 
-  Step-by-step instructions for solving  Puzzle 221, (38/64)   Diff: 5/9.9784
 -  Step-by-step instructions for solving  Puzzle 222, (40/64)   Diff: 5/9.8985
 -  Step-by-step instructions for solving  Puzzle 223, (38/64)   Diff: 6/92.6793
 -  Step-by-step instructions for solving  Puzzle 224, (40/64)   Diff: 6/99.9442
 -  Step-by-step instructions for solving  Puzzle 225, (37/64)   Diff: 7/859.6432
 -  Step-by-step instructions for solving  Puzzle 226, (42/64)   Diff: 7/589.8651
 -  Step-by-step instructions for solving  Puzzle 227, (42/64)   Diff: 8/5436.9843
 -  Step-by-step instructions for solving  Puzzle 228, (45/64)   Diff: 8/6425.6589