Smith, John Jay, ed., "Letters of Doctor Richard Hill and his children; or, the history of a family as told by themselves," Philadelphia: T. K. and P. O. Collins, Publishers, 1854, The Internet Archive, Internet website [1], accessed September 19, 2014. نسخة محفوظة 13 أبريل 2017 على موقع واي باك مشين.
web.archive.org
Smith, John Jay, ed., "Letters of Doctor Richard Hill and his children; or, the history of a family as told by themselves," Philadelphia: T. K. and P. O. Collins, Publishers, 1854, The Internet Archive, Internet website [1], accessed September 19, 2014. نسخة محفوظة 13 أبريل 2017 على موقع واي باك مشين.
