Italian Paintings of the Sixteenth Century: Ranuccio Farnese, 1541-1542 | National Gallery of Art https://www.nga.gov/research/publications/italian-paintings-sixteenth-century-0/italian-paintings-sixteenth-century-ranuccio-farnese-1541-1542
Reinach, and Bernard Berenson, continued to categorize it as a copy after Titian, or else