MLA
Mr. Henry Whiting, Mr. George Pratt and Mr. William Brooks Outside Mr. Whiting's Blacksmith Shop : with a Poster for the Ohio Dairy Co. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 72. https://digital.library.emory.edu/purl/945cc2fr1p-cor.
APA, 6th edition
Mr. Henry Whiting, Mr. George Pratt and Mr. William Brooks outside Mr. Whiting's Blacksmith Shop : with a poster for the Ohio Dairy Co. (Box 72). [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/945cc2fr1p-cor.
Chicago
“Mr. Henry Whiting, Mr. George Pratt and Mr. William Brooks Outside Mr. Whiting's Blacksmith Shop : with a Poster for the Ohio Dairy Co.” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 72. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/945cc2fr1p-cor.