MLA
Gonne, Maud, 1866-1953. Letter written by Maud Gonne to William Butler Yeats - [January/February 1909]. between 1909-01 and 1909-02. 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/040xpnw055-cor.
APA, 6th edition
Gonne, Maud, 1866-1953. (between 1909-01 and 1909-02)[Letter written by Maud Gonne to William Butler Yeats - [January/February 1909]]. 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/040xpnw055-cor.
Chicago
Gonne, Maud, 1866-1953, Letter written by Maud Gonne to William Butler Yeats - [January/February 1909], between 1909-01 and 1909-02, 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/040xpnw055-cor.