MLA
Gonne, Maud, 1866-1953. Letter written by Maud Gonne to William Butler Yeats - [January 1905]. January 1905. 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/4407wm39sm-cor.
APA, 6th edition
Gonne, Maud, 1866-1953. (January 1905)[Letter written by Maud Gonne to William Butler Yeats - [January 1905]]. 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/4407wm39sm-cor.
Chicago
Gonne, Maud, 1866-1953, Letter written by Maud Gonne to William Butler Yeats - [January 1905], January 1905, 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/4407wm39sm-cor.