Variations on Advanced Sudoku Logic Puzzles (Vol 1) 
 Chapter 37: Two Tournament Sudoku-15up Puzzles (numbers 123-124) 
 
-  Step-by-step instructions for solving  Puzzle 123, (129/225)   Diff: 28/9884.2111.C426.4496.5331.1243.6993
 -  Step-by-step instructions for solving  Puzzle 124, (126/225)   Diff: 29/9.6312.3243.11D1.1114.9976.4446.8465