Farington Diary, vol. 6, pp. 2136-37 (Sunday 2 October 1803); [?] Cook & Wedderburn, vol. 3, p. 189; WGC, p. 198, pl. 76a (version 3); H. Brocklebank, A Turn or two I'll walk to still my beating Mind: Commentary on a Private Collection, London, 1955, pp. 45-51.