My Samsung Galaxy S Duos 2 had Aldiko Reader on it with a few books in the library, I knew where they were on the SD card, and I had Calibre on my Mac. For some reason I don't remember, I reset the phone (but not the SD card) to factory default. Now most of those books, maybe all of them, are in Play Books, I can't find them in either phone storage or on the SD card, and Calibre can't find them either. The books did not come from Google Play Books, so they shouldn't be in the Play Books library on the phone, should they? I just downloaded a free ebook to my Mac (not from Google), and I want to put it on the phone. I haven't installed Aldiko or any other reader on the phone yet, because I want all my books to be accessible in the same app on the phone. I want either to put the new book in Play Books, or move the Play Books library to some other reader app that can also accept the new book. Where do I go from here?