Both Xinhua Bookstore and Boku Bookstore sell them. Go to the store and ask the clerk for a manual book. The clerk will tell you the details, as if it were about life and leisure. I bought mine in Boku.

In addition, there are e-books on the Internet, many of which are 1 yuan/book. However, it is more troublesome to draw a map by yourself, but the map is still very clear.

You can go and see it ~ ~ ~