Gaya APA

Incorporated, G. (1996). The Encylopedia Americana International Edition Volume 20 (Vol. 20). United States Of America: Grolier Incorporated.

Gaya MLA

Incorporated, Grolier. "The Encylopedia Americana International Edition Volume 20". Vol. 20 United States Of America: Grolier Incorporated, 1996. Text.