In terms of use, there are Chinese plaid book, math flat line book, English four-line plaid book and art white book.

There are paperbacks, thread-bound books, loose-leaf books and purse books on the binding.

There are also some books, four-grid books and so on that are not commonly used. Most of the above are for students, and there are books for professional occupation. I don't know. That's all I can do. There are four books of different sizes.