Royal Collection, Windsor Castle -- Clark (Kenneth): Drawings of Leonardo da Vinci in the Collection of Her Majesty the Queen at Windsor Castle, revised with the assistance of Carlo Pedretti, London, 1968, 3 vols., 4to, second edition -- Puyvelde (Leo van): Flemish Drawings in the Collection of His Majesty the King at Windsor Castle, London and New York, 1942, 4to -- Oppé (A.P.): English Drawings Stuart and Georgian Periods in the Collection of His Majesty the King at Windsor Castle, London, 1950, 4to -- Parker (K.T.): The Drawings of Hans Holbein in the Collection of His Majesty the King at Windsor Castle, Oxford and London, 1945, 4to, together 6 vols., plates and illustrations, original cloth, dust-jackets. (6)