Easy Sudoku Twelve Logic Puzzles (Vol 1) 
 Chapter 4: Twelve Easy (DiffLev 4) Sudoku-12 Puzzles (numbers 13-24) 
 
-  Step-by-step instructions for solving  Puzzle 13, (54/144)   Diff: 4/9954
 -  Step-by-step instructions for solving  Puzzle 14, (56/144)   Diff: 4/9971
 -  Step-by-step instructions for solving  Puzzle 15, (57/144)   Diff: 4/9962
 -  Step-by-step instructions for solving  Puzzle 16, (58/144)   Diff: 4/9993
 -  Step-by-step instructions for solving  Puzzle 17, (58/144)   Diff: 4/9932
 -  Step-by-step instructions for solving  Puzzle 18, (59/144)   Diff: 4/9971
 -  Step-by-step instructions for solving  Puzzle 19, (59/144)   Diff: 4/9962
 -  Step-by-step instructions for solving  Puzzle 20, (61/144)   Diff: 4/9991
 -  Step-by-step instructions for solving  Puzzle 21, (65/144)   Diff: 4/9981
 -  Step-by-step instructions for solving  Puzzle 22, (65/144)   Diff: 4/9963
 -  Step-by-step instructions for solving  Puzzle 23, (66/144)   Diff: 4/9992
 -  Step-by-step instructions for solving  Puzzle 24, (68/144)   Diff: 4/9991