It's possible:
* The name is slightly misspelled: There might be a similar name with a different spelling.
* The author is less well-known: They may not have published widely or have a strong online presence.
* The author goes by a pseudonym: The name Sebastiano A Tilli could be a pen name.
To help find information, please provide more context:
* What kind of books do you think they wrote? (Genre, subject matter, etc.)
* Do you have any other details about them? (Nationality, time period, any other works)
With more information, I might be able to help you locate this author.