Gaya APA
Hirokawa, O. (1980).
Introduction to Description of Volcanoes and Volcanic Rocks .
Bandung:
Direktorat Jenderal Pertambangan Umum.
Gaya MLA
Hirokawa, Osamu.
"Introduction to Description of Volcanoes and Volcanic Rocks".
Bandung:
Direktorat Jenderal Pertambangan Umum,
1980.
Text.