Easy Sudoku Seven Logic Puzzles (Vol 1) 
 Chapter 4: Fourteen Easy (DiffLev 4) Sudoku-7 Puzzles (numbers 15-28) 
 
-  Step-by-step instructions for solving  Puzzle 15, (27/49)   Diff: 4/9752
 -  Step-by-step instructions for solving  Puzzle 16, (27/49)   Diff: 4/9651
 -  Step-by-step instructions for solving  Puzzle 17, (28/49)   Diff: 4/9864
 -  Step-by-step instructions for solving  Puzzle 18, (29/49)   Diff: 4/9872
 -  Step-by-step instructions for solving  Puzzle 19, (29/49)   Diff: 4/8696
 -  Step-by-step instructions for solving  Puzzle 20, (30/49)   Diff: 4/9951
 -  Step-by-step instructions for solving  Puzzle 21, (30/49)   Diff: 4/9862
 -  Step-by-step instructions for solving  Puzzle 22, (30/49)   Diff: 4/8973
 -  Step-by-step instructions for solving  Puzzle 23, (31/49)   Diff: 4/9971
 -  Step-by-step instructions for solving  Puzzle 24, (31/49)   Diff: 4/9791
 -  Step-by-step instructions for solving  Puzzle 25, (32/49)   Diff: 4/9962
 -  Step-by-step instructions for solving  Puzzle 26, (32/49)   Diff: 4/9894
 -  Step-by-step instructions for solving  Puzzle 27, (32/49)   Diff: 4/9891
 -  Step-by-step instructions for solving  Puzzle 28, (32/49)   Diff: 4/9883