Gaya APA

John, D, A., Herris, D, M. (1980). The 1980 Eruptions of Mount St. Helens, Washington SO2 Emission Rates at Mount St, Helens from March 29 Through December 1980"" (Tahun 1980). Washington: U.S Geological Survey.

Gaya MLA

John, David, A.., Herris, David, M.. "The 1980 Eruptions of Mount St. Helens, Washington SO2 Emission Rates at Mount St, Helens from March 29 Through December 1980""". Tahun 1980 Washington: U.S Geological Survey, 1980. Text.