Cite

Autograph letter (draft), signed, to Samuel L. Clemens

MLA

Ferguson, Henry, 1848-1917. Autograph letter (draft), signed, to Samuel L. Clemens. Folder 3. [1899?]. https://collections.library.yale.edu/catalog/2047253.

APA, 6th edition

Ferguson, Henry, 1848-1917. (["Folder 3"])([1899?])[Autograph letter (draft), signed, to Samuel L. Clemens]. https://collections.library.yale.edu/catalog/2047253.