Gaya APA

Incorporated, G. (1981). Incyclopedia Americana 21: Orley To Photoengraving . United States of America: Grolier Incorporated Corporation.

Gaya MLA

Incorporated, Grolier. "Incyclopedia Americana 21: Orley To Photoengraving". United States of America: Grolier Incorporated Corporation, 1981. Text.