What is the content of Zhouyi besides the sixty-four hexagrams?

In addition to the sixty-four hexagrams, Zhouyi also contains poems, such as numbers and so on.

They are all sold in bookstores.

If you really can't buy it. You can download it online, or I can send it to you. Then you print it again. There's not much in it. I think 10 yuan is enough.