1Petty Vaughan to Thomas Jefferson, 29 March 1819 (Jefferson Papers)
Vaughan, Petty; and Guinea grass [index entry]
2Enclosure: Petty Vaughan’s Notes on Guinea Grass, 29 March 1819, enclosure number 2 in Petty Vaughan to Thomas … (Jefferson Papers)
Vaughan, Petty; and Guinea grass [index entry]