Thank you for the fast answer...
As I said, I translate the Abook completely (if you want, I will give you the language file if I have tested everything).
There are still questions:
1: You backed the ISBN and the ISSN number as a field. For me it would also be important and valuable, though have the ASIN = Amazon standard identification number. Many people, they buy ebooks on Amazon and so it would be good.
2: Also, it would be good to have the format. So different formats like eBook, hardcover, paperback, Kindle, Tolino etc.
3: Another question is: What does the "catalog" field mean?
(For me it is not a problem to add these features myself.) I have known Joomla for many years., Better is if the developer does the updates myself).
Maybe you are interested in implementing the feature.
Thanks Rene