Generally speaking, the way to tell whether a book is genuine is as follows:

Look at the paper The paper used for pirated books is very thin in your hand, usually yellow-gray and has poor elasticity. Tearing a small hole, you can find that the fracture is smooth, while the paper for genuine books is thick and white, with high wood pulp content, and you can find that the fracture is not smooth and there are trace fibers.

Look at printing. Pirated books are usually vague or even weak; There are often traces of tape, scissors or other imposition, and graphics often bend; Pirated books are usually not revised, so all kinds of traces produced in the process of plate making are obvious; Pirated books have uneven ink color, no gap between thick strokes and light strokes, and look like a ghost.

There are many mistakes in the words, words, sentences and punctuation of pirated books, and some of them are typos.