"none" as author

[Azur]

https://www.goodreads.com/author/show...

[Krazykiwi]

For this one in particular, check the changelog carefully, and also check if the book is attached to other editions.

It's a favourite for authors who are trying to remove out of print books to change the author to, and you can often just undo (and perhaps flag) a bunch of edits to resurrect the listing.

(If you do retrieve that kind of listing, do leave a librarian note telling the author not to remove valid data or to remove OOP books.)

[Azur]

"autor" author in several languages https://www.goodreads.com/author/show...

"unbekannt" German for unknown https://www.goodreads.com/author/show...

"x" https://www.goodreads.com/author/show...