These books contain puzzles with a group size between 12 and 16, presenting a much greater challenge than the quilted Sudoku-by5 puzzles with a group size of 9 on a 21x21 grid. The 'Variations on Advanced Sudoku'' books contain a few examples of the different puzzle types available in this catalogue, with puzzles at many of the available difficulty levels. The 'Variations' books are available either by level, i.e., all the puzzles in the book are the same level of difficulty (easy, difficult, challenging, etc) or with all levels in a single (but much larger) book. For editions that are available in print, the on-line information includes detailed step-by-step solutions for each puzzle, as well as other information available in all eBook editions.
| Book Title | Vol | Puzzle Count | On-Line Info | Edition Availability | |||
| Paperback | |||||||
| Variations on Advanced Sudoku | 1 | 190 | Solutions | $7.99 | eStore | ||
| Easy Sudoku Twelve | 1 | 190 | Solutions | $7.99 | eStore | ||
| Medium Sudoku Twelve | 1 | 190 | Solutions | $7.99 | eStore | ||
| Difficult Sudoku Twelve | 1 | 190 | Solutions | $7.99 | eStore | ||
| Challenging Sudoku Twelve | 1 | 190 | Solutions | $7.99 | eStore | ||
| Tournament Sudoku Twelve | 1 | 190 | Solutions | $7.99 | eStore | ||