1John Vaughan to Thomas Jefferson, 12 February 1818 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
2Caspar Wistar to Thomas Jefferson, 27 April 1815 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
3American Philosophical Society to Thomas Jefferson, 20 January 1815 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
4John Vaughan to Thomas Jefferson, 9 January 1815 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
5John Vaughan to Thomas Jefferson, 22 January 1818 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
6Robert M. Patterson to Thomas Jefferson, 23 January 1818 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
7Caspar Wistar to Thomas Jefferson, 20 May 1817 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
8Peter S. Du Ponceau to Thomas Jefferson, 22 January 1818 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
9Thomas Jefferson to Robert M. Patterson, 15 February 1818 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]
10Thomas Jefferson to Robert M. Patterson, 8 February 1815 (Jefferson Papers)
Wistar, Caspar; and American Philosophical Society [index entry]