These books all have special teaching material shops. You can check it online and ask the local textbook store. Sometimes, there will be a particularly large Xinhua Bookstore. I used to buy books for my nephew at the textbook store. There is another way, that is, through friends or school teachers, to borrow one from the students in the original grade, or it will be better if the students in the graduating class still keep it. Then you use the borrowed books and give your books to your classmates. After all, it didn't take long for school to start, and the book was quite new.