MLA
Teich, Curt, and Co. Lift Every Voice and Sing : a Sculpture of a Harp Made of People. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 69. https://digital.library.emory.edu/purl/832r4xgxh8-cor.
APA, 6th edition
Teich, C., & C. Lift Every Voice and Sing : a sculpture of a harp made of people (Box 69) [Postcards]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/832r4xgxh8-cor.
Chicago
Teich, Curt, and Co. “Lift Every Voice and Sing : a Sculpture of a Harp Made of People.” Postcards. Robert Langmuir African American Photograph Collection, n.d. Box 69. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/832r4xgxh8-cor.