APA (7th ed.) Citation

Thurber, G. (1854). Thurber, George undated postscript. Zenodo.

Chicago Style (17th ed.) Citation

Thurber, George. Thurber, George Undated Postscript. Zenodo, 1854.

MLA (9th ed.) Citation

Thurber, George. Thurber, George Undated Postscript. Zenodo, 1854.

Warning: These citations may not always be 100% accurate.