Gaya APA
Berita Berkala Vulkanologi Edisi Khusus : Gunung Merapi No. 122 1990. (1990).
Bandung:
Department of Mines and Energy.
Gaya MLA
Berita Berkala Vulkanologi Edisi Khusus : Gunung Merapi No. 122 1990.
.
Bandung:
Department of Mines and Energy,
1990.
Text.