Gaya APA
Newhall, C, G. (1988).
Historical Unrest at Large Calderas of The World Vol. I .
Washington:
United States Government Printing Office.
Gaya MLA
Newhall, Christopher, G.
"Historical Unrest at Large Calderas of The World Vol. I".
Washington:
United States Government Printing Office,
1988.
Text.