MLA
Gonne, Maud, 1866-1953. Letter written by Maud Gonne to William Butler Yeats - February 2 [1901]. February 2, 1901. Maud Gonne and W.B. Yeats Papers, circa 1890-1938. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/081wdbrx4r-cor.
APA, 6th edition
Gonne, Maud, 1866-1953. (February 2, 1901)[Letter written by Maud Gonne to William Butler Yeats - February 2 [1901]]. Maud Gonne and W.B. Yeats Papers, circa 1890-1938, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/081wdbrx4r-cor.
Chicago
Gonne, Maud, 1866-1953, Letter written by Maud Gonne to William Butler Yeats - February 2 [1901], February 2, 1901, Maud Gonne and W.B. Yeats Papers, circa 1890-1938, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/081wdbrx4r-cor.