APA Style
Grolier : Encyclopedia of knowledge Vol 20. (1990).
Danbury:
Grolier Incorporated.
Chicago Style
Grolier : Encyclopedia of knowledge Vol 20.
.
Danbury:
Grolier Incorporated,
1990.
Text.
MLA Style
Grolier : Encyclopedia of knowledge Vol 20.
.
Danbury:
Grolier Incorporated,
1990.
Text.
Turabian Style
Grolier : Encyclopedia of knowledge Vol 20.
Danbury:
Grolier Incorporated,
1990.
Print.