Question: Robert Rankin wrote a novel based on what painting, housed in the Museo del Prado in Madrid since 1939?
Sentence (from "Portrait of Camilla Gonzaga and Her Three Sons"): Portrait of Camilla Gonzaga and Her Three Sons is a painting attributed to the Italian Mannerist artist Parmigianino and others, executed around 1539-1540 and housed in the Museo del Prado, Madrid, Spain.
Relevant evidence: No