MLA
McKay, William. Receipt to William H. Scott, Sr. from William McKay, October 31, 1888. 1888. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 1, Folder 9. https://digital.library.emory.edu/purl/81937pvnw5-cor.
APA, 6th edition
McKay, W. (1888). Receipt to William H. Scott, Sr. from William McKay, October 31, 1888 (Box 1, Folder 9) [Receipts (financial records)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/81937pvnw5-cor.
Chicago
McKay, William. “Receipt to William H. Scott, Sr. from William McKay, October 31, 1888.” Receipts (financial records). William H. Scott Family Papers, 1848-1982, 1888. Box 1, Folder 9. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/81937pvnw5-cor.