Gaya APA
Korosec, M, A. (1980).
The 1980 Eruption of Mount St. Helens (Juni 1980).
Washington:
Washington State Department of Natural Resources.
Gaya MLA
Korosec, Michael, A..
"The 1980 Eruption of Mount St. Helens".
Juni 1980
Washington:
Washington State Department of Natural Resources,
1980.
Text.