APA (7th ed.) Citation

Mamay, S. H. (1976). Paleozoic origin of the cycads. United States Department of the Interior, Geological Survey.

Chicago Style (17th ed.) Citation

Mamay, Sergius H. Paleozoic Origin of the Cycads. Washington: United States Department of the Interior, Geological Survey, 1976.

MLA (9th ed.) Citation

Mamay, Sergius H. Paleozoic Origin of the Cycads. United States Department of the Interior, Geological Survey, 1976.

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