Gaya APA
WHY ON EARTH ?. (1988).
:
National Geographic Society.
Gaya Chicago
WHY ON EARTH ?.
.
:
National Geographic Society,
1988.
Printed Book.
Gaya MLA
WHY ON EARTH ?.
.
:
National Geographic Society,
1988.
Printed Book.
Gaya Turabian
WHY ON EARTH ?.
:
National Geographic Society,
1988.
Printed Book.