Have you ever systematically studied books about writing modern poems?

There is no specific systematic theory of new poetry, so there is no book for you to study systematically. . . . . . Just look at the image and the artistic conception, which are all in the middle school Chinese textbooks. Also, I personally suggest that you read modern poetry until 1950 was born as a poet. Those so-called modern poets behind are no longer poets, but cultural traffickers (definitely not knocking over a boat with one pole). If you really want to see it, take a look at Mr. Zhu Guangqian's On Poetry, which is a fine work connecting the preceding with the following.