Tilling, R. I. (1984). Eruptions of Mount St. Helens: Past, present, and future. Dept. of the Interior, U.S. Geological Survey ; For sale by the Supt. of Docs., U.S. G.P.O..
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रTilling, Robert I. Eruptions of Mount St. Helens: Past, Present, and Future. [Reston, Va.?] : Washington, D.C.: Dept. of the Interior, U.S. Geological Survey ; For sale by the Supt. of Docs., U.S. G.P.O., 1984.
एमएलए (8वां संस्करण) प्रशस्ति पत्रTilling, Robert I. Eruptions of Mount St. Helens: Past, Present, and Future. Dept. of the Interior, U.S. Geological Survey ; For sale by the Supt. of Docs., U.S. G.P.O., 1984.
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