It's possible that:
* The name is misspelled: Check the spelling carefully and try searching again.
* The author is not well-known: They may be a lesser-known author or write in a niche genre.
* The author has a different name: They may use a pseudonym or have changed their name.
To help me find the author, please provide more context:
* What genre do they write in?
* Do you know anything about their nationality or language?
* Do you have any specific titles or works by this author?
With more information, I can help you find out more about "Siegfried Odermatt" or whoever you are looking for.