MLA
Galleries, Brady's National Photographic Portrait. Union General Samuel P. Heintzelman. E. and H. T. Anthony, 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 22, Folder 26. https://digital.library.emory.edu/purl/764gmsbdkt-cor.
APA, 6th edition
Galleries, B. N. P. P. (1861). Union general Samuel P. Heintzelman (Box 22, Folder 26) [Cartes-de-visite (card photographs)]. E. and H. T. Anthony; Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/764gmsbdkt-cor.
Chicago
Galleries, Brady's National Photographic Portrait. “Union General Samuel P. Heintzelman.” Cartes-de-visite (card photographs). Civil War Collection. New York City, NY: E. and H. T. Anthony, 1861. Box 22, Folder 26. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/764gmsbdkt-cor.