Recently I copied a few PDFs into iBooks from Windows via Dropbox, and then deleted the files on Dropbox. Little did I know that the files on Dropbox were my only Windows copies (I thought drag-and-drop on Windows to Dropbox would copy the files, not move them). So now I need to get those files from iBooks back to Windows. How do I do it? Dropbox has no option for this that I can find.