We aren't yet able to add books that are not listed on Amazon. We have to add all the data for the book manually so it is very time-consuming. However, we will do this if the book is something you want to index - you would need to send us title, sub-title, author, publisher, publication date, format, # of pages and cover image (scan or photo). We do hope in the future to add a feature that will allow members to add the data for their own books, in the same way members can add their own recipes.
Is there any particular reason for the 3 books you mention that you couldn't add the book we have listed to your Bookshelf? I can understand there would be a problem if we hadn't got any edition of the books you own listed, but for these 3, they are listed and 2 are indexed.