APA (7th ed.) Citation

Sinclair, U. (1926). Letters to Judd: An American workingman. The author.

Chicago Style (17th ed.) Citation

Sinclair, Upton. Letters to Judd: An American Workingman. Pasadena, Calif.: The author, 1926.

MLA (9th ed.) Citation

Sinclair, Upton. Letters to Judd: An American Workingman. The author, 1926.