If the ebook is in the Reader library, not the ADE library, you can import
it using ADE's 'Add Item To Library' function. You will need to know the
name of the ebook and its file location. Then, open ADE, click on the
small arrow next to the word 'Library' in Library view, and you should see
the 'Add Item...' choice on the submenu. Once you choose it, then point
ADE to the library where your PDF is. You know the drill from there....