1Thomas Jefferson’s Account with Joseph Milligan, [8–10 March 1809] (Jefferson Papers)
Garnett, John; Nautical Almanac and Astronomical Ephemeris [index entry]
2Joseph Milligan to Thomas Jefferson, 14 December 1814 (Jefferson Papers)
Garnett, John; Nautical Almanac and Astronomical Ephemeris [index entry]
3Enclosure: Thomas Jefferson’s Account with Joseph Milligan, [ca. 6 February 1818] (Jefferson Papers)
Garnett, John; Nautical Almanac and Astronomical Ephemeris [index entry]