90 books
Sudoku Hard Book 18
Sudoku Easy Book 5
Sudoku Medium Book 26
Sudoku Easy Book 20
Sudoku Medium Book 29
Sudoku Medium Book 30
Sudoku Easy Book 12
Sudoku Medium Book 15
Sudoku Medium Book 14
Sudoku Hard Book 30
Sudoku Hard Book 19
Sudoku Easy Book 27
Sudoku Easy Book 14
Sudoku Medium Book 28
Sudoku Easy Book 11
Sudoku Medium Book 5
Sudoku Hard Book 1
Sudoku Medium Book 1