What has the author Joseph Conrad Frantz written?

There seems to be a misunderstanding. There is no author named "Joseph Conrad Frantz".

You are likely thinking of Joseph Conrad, a renowned Polish-British writer. He is famous for his novels like:

* Heart of Darkness

* Lord Jim

* Nostromo

* The Secret Agent

* The Nigger of the "Narcissus"

Please double-check the name or provide more information if you are referring to someone else.