Let me put it the other way round. If you are writing a book review, why would you want to "repeat content already published somewhere"? What content are you planning to repeat?
Perhaps you mean that you want to quote extracts from the book in your review. If so, that's completely legitimate, and it won't cause you any problems - provided the quotes are short, and you still provide plenty of original content.
But if you mean you want to copy large amounts of content from other reviews, that's another matter. It's called plagiarism, and it will quite possibly get you into trouble.
If I have misunderstood your question, please clarify it.