Não informado. (2017). Earthquakes & Volcanoes. U.S. Geological Survey.
Chicago-viite (17. p.)Não informado. Earthquakes & Volcanoes. Reston, Va: U.S. Geological Survey, 2017.
MLA-viite (8. p.)Não informado. Earthquakes & Volcanoes. U.S. Geological Survey, 2017.
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