Gaya APA
World Book, Inc. (2014).
The World Book Encyclopedia Volume 20 : U - V .
United States of America:
.
Gaya Chicago
World Book, Inc.
The World Book Encyclopedia Volume 20 : U - V.
United States of America:
,
2014.
Teks.
Gaya MLA
World Book, Inc.
The World Book Encyclopedia Volume 20 : U - V.
United States of America:
,
2014.
Teks.
Gaya Turabian
World Book, Inc.
The World Book Encyclopedia Volume 20 : U - V.
United States of America:
,
2014.
Teks.