Ethel Clifford Rosenberg, known professionally as Eth Clifford or Ruth Bonn Penn, was an American children's fiction writer, best known as the author of the *Flatfoot Fox* and *Jo-Beth* and *Mary Rose Mysteries* series. Clifford's husband, David Rosenberg, encouraged her to begin writing, and she did so, publishing her first novel for adults in 1949. Her subsequent books were written for children, and her 1979 novel *Help I'm A Prisoner in the Library!* earned her the prestigious 1982 Young Hoosier Award.
Together with her husband, she founded David-Stewart Publishing company. When co-authoring a book, the two would write under the portmanteau pen name of David Clifford.
Source: [Wikipedia](https://en.wikipedia.org/wiki/Eth_Clifford)
