Gaya APA

Foxworthy, B, L., Hill, M. (1982). Volcanic Eruption Of 1980 at Mount St. Helens The First 100 days . Washington: United States Goverment Printing Office..

Gaya MLA

Foxworthy, Bruce, L.., Hill, Mary. "Volcanic Eruption Of 1980 at Mount St. Helens The First 100 days". Washington: United States Goverment Printing Office., 1982. Text.