Variations on Advanced Sudoku Logic Puzzles (Vol 1) 
 Chapter 29: Four Difficult Sudoku-15 Puzzles (numbers 95-98) 
 
-  Step-by-step instructions for solving  Puzzle 95, (101/225)   Diff: 10/99.9465.2376
 -  Step-by-step instructions for solving  Puzzle 96, (115/225)   Diff: 11/999.9998.3242
 -  Step-by-step instructions for solving  Puzzle 97, (113/225)   Diff: 12/9989.4898.9765
 -  Step-by-step instructions for solving  Puzzle 98, (130/225)   Diff: 14/99.9969.9973.4893