MLA
Artvue Post Card Co. (New York, N.Y.). Baltimore Bullets Clinic Day, Camp Alpha Omega, Carroll County, Maryland. unknown. Robert Langmuir African American Photograph Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/030prr4xkq-cor.
APA, 6th edition
Artvue Post Card Co. (New York, N.Y.). (unknown)[Baltimore Bullets Clinic Day, Camp Alpha Omega, Carroll County, Maryland]. Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/030prr4xkq-cor.
Chicago
Artvue Post Card Co. (New York, N.Y.), Baltimore Bullets Clinic Day, Camp Alpha Omega, Carroll County, Maryland, unknown, Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/030prr4xkq-cor.