Gaya APA
Koyanagi, R, Y. et al (1988).
USGS/USAID Suport of the Seismic Program at the Merapi Volcano Observatory, May - June 1988. .
Bandung:
Pusat Vulkanologi dan Mitigasi Bencana Geologi.
Gaya MLA
Koyanagi, Robert, Y.. et al.
"USGS/USAID Suport of the Seismic Program at the Merapi Volcano Observatory, May - June 1988.".
Bandung:
Pusat Vulkanologi dan Mitigasi Bencana Geologi,
1988.
Text.