Gaya APA
Incorporated, G. (1973).
The New Book Of Knowledge: jilid 20 W-X-Y-Z .
United State Of America:
Grolier Incorporated.
Gaya MLA
Incorporated, Grolier.
"The New Book Of Knowledge: jilid 20 W-X-Y-Z".
United State Of America:
Grolier Incorporated,
1973.
Text.