Personally I would read a book on statistical physics instead, since this is where the study of 'emergence' began. The Feynman lectures would be good for this.

I actually haven't found many good books for 'Complex systems', but if you want to take a shot anyway, I would look at https://academic.oup.com/book/25504 and https://press.princeton.edu/books/paperback/9780691122045/cr...