MLA
Kirby, F. M., and Co. Four Little Pickaninnies in New Orleans, La. : African American Children Sitting on a Porch, One in a Rocking Chair Playing with a Dog [Hand Colored]. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 73. https://digital.library.emory.edu/purl/286nzs7h61-cor.
APA, 6th edition
Kirby, F. M., & C. Four little pickaninnies in New Orleans, La. : African American children sitting on a porch, one in a rocking chair playing with a dog [hand colored] (Box 73) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/286nzs7h61-cor.
Chicago
Kirby, F. M., and Co. “Four Little Pickaninnies in New Orleans, La. : African American Children Sitting on a Porch, One in a Rocking Chair Playing with a Dog [Hand Colored].” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 73. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/286nzs7h61-cor.