Medium Sudoku Twelve Logic Puzzles (Vol 1) 
 Chapter 55: Two Medium (DiffLev 6-7) Voluntaryism Puzzles (numbers 189-190) 
 
-  Step-by-step instructions for solving  Puzzle 189, (78/144)   Diff: 6/99.9991
 -  Step-by-step instructions for solving  Puzzle 190, (82/144)   Diff: 7/999.9992