Gaya APA
The World Book Encyclopedia : W-X-Y-Z Volume 21. (2006).
chicago:
World book.
Gaya Chicago
The World Book Encyclopedia : W-X-Y-Z Volume 21.
Volume 21.
chicago:
World book,
2006.
Buku.
Gaya MLA
The World Book Encyclopedia : W-X-Y-Z Volume 21.
Volume 21.
chicago:
World book,
2006.
Buku.
Gaya Turabian
The World Book Encyclopedia : W-X-Y-Z Volume 21.
chicago:
World book,
2006.
Buku.