Não informado. (2017). Earthquakes & Volcanoes. U.S. Geological Survey.
Chicagoスタイル(17版)引用形式Não informado. Earthquakes & Volcanoes. Reston, Va: U.S. Geological Survey, 2017.
MLA(8版)引用形式Não informado. Earthquakes & Volcanoes. U.S. Geological Survey, 2017.
警告: この引用は必ずしも正確ではありません.