1Thomas Jefferson to Robert Patterson, 7 March 1811 (Jefferson Papers)
Garnett, John; Nautical Almanac and Astronomical Ephemeris [index entry]
2Thomas Jefferson to Robert Patterson, 21 March 1811 (Jefferson Papers)
Garnett, John; Nautical Almanac and Astronomical Ephemeris [index entry]
3Thomas Jefferson to Robert Patterson, 10 November 1811 (Jefferson Papers)
Garnett, John; Nautical Almanac and Astronomical Ephemeris [index entry]