Variations on Intermediate Sudoku Logic Puzzles (Vol 1) 
 Chapter 3: Four Easiest Sudoku-7 Puzzles (numbers 1-4) 
 
-  Step-by-step instructions for solving  Puzzle 1, (17/49)   Diff: 2/92
 -  Step-by-step instructions for solving  Puzzle 2, (18/49)   Diff: 2/93
 -  Step-by-step instructions for solving  Puzzle 3, (19/49)   Diff: 2/91
 -  Step-by-step instructions for solving  Puzzle 4, (23/49)   Diff: 2/93