APA (7th ed.) Citation

Berdan, J. M. (1964). The Helderberg Group and the position of the Silurian-Devonian boundary in North America. United States Department of the Interior, Geological Survey.

Chicago Style (17th ed.) Citation

Berdan, Jean Milton. The Helderberg Group and the Position of the Silurian-Devonian Boundary in North America. Washington, D.C.: United States Department of the Interior, Geological Survey, 1964.

MLA (9th ed.) Citation

Berdan, Jean Milton. The Helderberg Group and the Position of the Silurian-Devonian Boundary in North America. United States Department of the Interior, Geological Survey, 1964.