15 Training Techniques in Sudoku ranging from Easy to Diabolical, each with 14 Sudoku puzzles to solve. Contains 210 Sudoku puzzles of varying difficulty. Each lesson and set of puzzles concludes with a congratulatory recognition themed to that lesson.
Cannot read diagrams on a Kindle and even magnified on a computer screen still too small. The PDF download doesn’t work - probably too old. Maybe OK in hard copy but ???