デイヴィッド・ジョンストン
edu/Reports/bulletin/contents.cfm?issue=special#sean_0505.
1 2 Alden, Andrew (2010年). “Mount St. Helens Eruption of 1980: The man who gave everything”. 2010年3月24日閲覧。
↑ Christiansen, R. L.; Peterson, D. W. “Chronology of the 1980 Eruptive Activity”. In Lipman, Peter W., and Mullineaux, Donal R. The 1980 eruptions of Mount St. Helens, Washington. USGS Professional Paper. 1250. アメリカ地質調査所. http://vulcan.wr.usgs.gov/Volcanoes/MSH/Publications/PP1250/ChristiansenPeterson/chronology_1980_activity.html
1 2 Dzurisin, Daniel (February 2003). “A comprehensive approach to monitoring volcano deformation as a window on the eruption cycle”. Reviews of Geophysics (アメリカ地球物理学連合) 41 (1): 1001. Bibcode: 2003RvGeo..41.