MLA
Chase-Riboud, Barbara. Telegram from "David Riboud" to His Grandmother, Vivian May Chase (Philadelphia, Pennsylvania) - July 23, 1964. 1964. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 1, Folder 4. https://digital.library.emory.edu/purl/559q2bvr4s-cor.
APA, 6th edition
Chase-Riboud, B. (1964). Telegram from "David Riboud" to his grandmother, Vivian May Chase (Philadelphia, Pennsylvania) - July 23, 1964 (Box 1, Folder 4) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/559q2bvr4s-cor.
Chicago
Chase-Riboud, Barbara. “Telegram from ‘David Riboud’ to His Grandmother, Vivian May Chase (Philadelphia, Pennsylvania) - July 23, 1964.” Letters (correspondence). Barbara Chase-Riboud Papers, 1964. Box 1, Folder 4. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/559q2bvr4s-cor.