MLA
Berryman, N. G. Letter from N. G. Berryman (Auburn, Missouri) to Robert Paine - January 22, 1852. 1852. Pitts Theology Library, Box 1, Folder 1. https://digital.library.emory.edu/purl/344pk0p3sx-cor.
APA, 6th edition
Berryman, N. G. (1852). Letter from N. G. Berryman (Auburn, Missouri) to Robert Paine - January 22, 1852 (Box 1, Folder 1) [Letters (correspondence)]. Pitts Theology Library. https://digital.library.emory.edu/purl/344pk0p3sx-cor.
Chicago
Berryman, N. G. “Letter from N. G. Berryman (Auburn, Missouri) to Robert Paine - January 22, 1852.” Letters (correspondence). Robert Paine Papers, 1828-1882, 1852. Box 1, Folder 1. Pitts Theology Library. https://digital.library.emory.edu/purl/344pk0p3sx-cor.