Challenging Sudoku Twelve Logic Puzzles (Vol 1) 
 Chapter 25: Two Challenging (DiffLev 17-20) Exhaustingly Puzzles (numbers 129-130) 
 
-  Step-by-step instructions for solving  Puzzle 129, (88/144)   Diff: 17/9.9424.31C4.3446.7993
 -  Step-by-step instructions for solving  Puzzle 130, (95/144)   Diff: 20/9631.2A13.22A2.3489.8799