1John Hollins to Thomas Jefferson, 27 January 1811 (Jefferson Papers)
agriculture; use of gypsum in [index entry]
2John Hollins to Thomas Jefferson, 9 February 1810 (Jefferson Papers)
agriculture; use of gypsum in [index entry]
3John Hollins to Thomas Jefferson, 18 March 1810 (Jefferson Papers)
agriculture; use of gypsum in [index entry]
4John Hollins to Thomas Jefferson, 22 April 1810 (Jefferson Papers)
agriculture; use of gypsum in [index entry]