APA (7th ed.) Citation

Poppe, B. B. (1979). Historical survey of U.S. seismograph stations. Dept. of the Interior, Geological Survey.

Chicago Style (17th ed.) Citation

Poppe, Barbara B. Historical Survey of U.S. Seismograph Stations. [Reston, Va.]: Dept. of the Interior, Geological Survey, 1979.

MLA (9th ed.) Citation

Poppe, Barbara B. Historical Survey of U.S. Seismograph Stations. Dept. of the Interior, Geological Survey, 1979.