Adding Books by ISBN
It doesn't matter if you enter a 10-digit or a 13-digit ISBN number. Citavi can determine the other number if the original entry is not found.
Check that the imported references are actually normal books and not edited books or conference proceedings. Not all catalogs include this information. If you need to change a book's reference type, on the Reference menu, click Choose reference type.
If you consistently have no results, you may want to change the selected catalogs by following the steps below. For example, if you want to add works of fiction to your project, you may have better results if you select an online bookseller's catalog rather than an academic library catalog.
Not all catalogs provide complete bibliographic information. Citavi enters the source of the imported bibliographic information in the Source field. Once you obtain a copy of the book, you should double check the bibliographic information against the actual copy. Then you can go back to the Source field and select Original source from the dropdown menu.