1William F. Gray to Thomas Jefferson, 20 January 1820 (Jefferson Papers)
Bowditch, Nathaniel; The New American Practical Navigator [index entry]
2Joseph Milligan to Thomas Jefferson, 11 May 1818 (Jefferson Papers)
Bowditch, Nathaniel; The New American Practical Navigator [index entry]
3William F. Gray to Thomas Jefferson, 30 November 1818 (Jefferson Papers)
Bowditch, Nathaniel; The New American Practical Navigator [index entry]