APA (7th ed.) Citation

Geological Survey (U.S.) & ProQuest (Firm). (1925). Department of the Interior Hubert Work, Secretary United States Geological Survey George Otis Smith, Director Professional Paper 136. The Flora of the Ripley Formation. [publisher not identified].

Chicago Style (17th ed.) Citation

Geological Survey (U.S.) and ProQuest (Firm). Department of the Interior Hubert Work, Secretary United States Geological Survey George Otis Smith, Director Professional Paper 136. The Flora of the Ripley Formation. Washington: [publisher not identified], 1925.

MLA (9th ed.) Citation

Geological Survey (U.S.) and ProQuest (Firm). Department of the Interior Hubert Work, Secretary United States Geological Survey George Otis Smith, Director Professional Paper 136. The Flora of the Ripley Formation. [publisher not identified], 1925.