Perhaps Brettingham Account Book, p. 42; Christie's sale catalogue, 28 June 1814 (82); WGC, pp. 82, 109, 197, pl. 75b; J.J. Emerick, The Tempietto del Clitumno near Spoleto, 1998, vol. 2, p. 121, n. 22; Feigen 2010, unpaginated; D. Marignoli, 'Richard Wilson e il Tempietto Clitunno', Spoletium, vol. 48, no. 4, 2011, pp. 106-113