MLA
Founders Hall. Penn School, St. Helena Island, South Carolina. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/218dfn2z6q-cor.
APA, 6th edition
Founders Hall. Penn School, St. Helena Island, South Carolina (Box 69). [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/218dfn2z6q-cor.
Chicago
“Founders Hall. Penn School, St. Helena Island, South Carolina.” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 69. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/218dfn2z6q-cor.