APA (7th ed.) Citation

Whitman, W. (1875). [Portrait of Walt Whitman]. [publisher not identified].

Chicago Style (17th ed.) Citation

Whitman, Walt. [Portrait of Walt Whitman]. [United States?]: [publisher not identified], 1875.

MLA (9th ed.) Citation

Whitman, Walt. [Portrait of Walt Whitman]. [publisher not identified], 1875.

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