Rudolf Wittkower pointed that this is related to Schor's painting in the Quirinal Palace, Rome. A study at Windsor is almost identical to this drawing, although Wittkower noted that the present drawing is arguably a little freer in execution, A. Blunt and H.L. Cooke, The Roman Drawings of the XVII and XVIII Centuries in the Collection of Her Majesty the Queen at Windsor Castle, London, 1960, fig. 99