Yeah - that is just and simply a problem of the UI - nothing else. e.g. being able to use parts of the screen for different books, using two screens at once, etc
Or you could just print out those 4 pages. It would still be easier to do the rest of the research.
Or two / three / four devices. I mean - you are comparing four p-books (parallel) to one device, thats unfair. So use 4 e-book-reader (they will get cheaper) and compare them to 4 p-books
Even better: You can compare two different sets of four poems
Oh well, let's just agree that in most cases e-books win hands on, but some usage can still be found for p-books