Booth Notes, Doc. 5, p. 4; The General Advertiser and Morning Intelligence, no. 468, 2 May 1778, p. 4; Report and Transactions of the Devonshire Society for the Advancement of Science, Literature and Art, vol 19, 1882, p. 162; WGC, pp. 89, 183, pl. 48c (as Penn Ponds, Richmond Park); Cardiff 1961, pp. 22-23 (as Penn Ponds); Solkin 1982, pp. 205-7; Quilley & Bonehill 2004, p. 195; Wilson and Europe 2014 (138)