Ethel Clifford Rosenberg (December 25, 1915 – April 1, 2003)[2] 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 was taught to read in a one-room schoolhouse, and grew up an avid reader.
[1] At the age of sixteen, she met her future husband, David Rosenberg, at a poetry reading in Brooklyn.
That her married name was Ethel Rosenberg and her first two books prominently featured a character named Julius is a remarkable coincidence, and apparently helped drive her subsequent use of the Eth Clifford byline.
When co-authoring a book, the two would write under the portmanteau pen name of David Clifford.