Variations on Intermediate Sudoku Logic Puzzles (Vol 1) 
 Chapter 44: Four Easy Sudoku-8-X Puzzles (numbers 249-252) 
 
-  Step-by-step instructions for solving  Puzzle 249, (27/64)   Diff: 3/951
 -  Step-by-step instructions for solving  Puzzle 250, (29/64)   Diff: 3/991
 -  Step-by-step instructions for solving  Puzzle 251, (31/64)   Diff: 4/9962
 -  Step-by-step instructions for solving  Puzzle 252, (34/64)   Diff: 4/9962