MLA
Russell, George William, 1867-1935. Letter from George Russell (AE) (Dublin) to Augusta Gregory. Letter contains illustrations - December 18, 1900. December 18, 1900. Gregory Family Papers, 1770-1956. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/163stqjqfb-cor.
APA, 6th edition
Russell, George William, 1867-1935. (December 18, 1900)[Letter from George Russell (AE) (Dublin) to Augusta Gregory. Letter contains illustrations - December 18, 1900]. Gregory Family Papers, 1770-1956, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/163stqjqfb-cor.
Chicago
Russell, George William, 1867-1935, Letter from George Russell (AE) (Dublin) to Augusta Gregory. Letter contains illustrations - December 18, 1900, December 18, 1900, Gregory Family Papers, 1770-1956, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/163stqjqfb-cor.