As far as I can tell, you can use any PDF but...
- The PDF is not the best format for reading, it does usually not allow the reader to adjust settings like police type/size (that you might like to change for comfort)
- I'm not sure that the Tolino has a pdf "Reflow" technology (bookeen does: https://youtu.be/7sf5DyUWn-... ) to make reading better...