APA (7th ed.) Citation

Littlefield, D. F. (1971). Twentieth century American nature writing: A study in themes and techniques. [publisher not identified].

Chicago Style (17th ed.) Citation

Littlefield, Daniel F. Twentieth Century American Nature Writing: A Study in Themes and Techniques. [Stillwater, Okla.]: [publisher not identified], 1971.

MLA (8th ed.) Citation

Littlefield, Daniel F. Twentieth Century American Nature Writing: A Study in Themes and Techniques. [publisher not identified], 1971.