There are 4 novels - Thriller, Mystery, Romance and Science Fiction - writen by Ambrose, Richards, Hooper and Walsh, and published by Alpha, Beta, Gamma and Theta not in necessarily in the same order.
* The book by Ambrose is published by Theta.
* The Thriller is published by Alpha.
* The Science Fiction novel is by Hooper and is not published by Gamma.
* The Romance novel is by Walsh. Who are the Author and the Publisher of each novels?