Sometimes you may need to merge several books into one. For example, after scan, when you get several parts of the same books or several versions of one book in different formats.
To merge books:
1. Select the books you want to merge using Crtl, Shift buttons
2. Click Books -> Merge Books menu
3. In the Merge window select the target (primary) book, that you want to keep in the library
4. Check the box "Delete source books" if you want to delete the secondary books
5. Press OK, and the ebook files from secondary books will be linked to the target (primary) book