MLA
Co., Nationwide Post Card. Ross Avenue Motel, Dallas, Tex. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 71. https://digital.library.emory.edu/purl/6042rbnztv-cor.
APA, 6th edition
Co., N. P. C. Ross Avenue Motel, Dallas, Tex. (Box 71) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6042rbnztv-cor.
Chicago
Co., Nationwide Post Card. “Ross Avenue Motel, Dallas, Tex.” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 71. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/6042rbnztv-cor.