APA استشهاد

Britannica, E. (1972). Britannica year book of science and the future. U.S.A.

استشهاد بنمط شيكاغو

Britannica, Encyclopaedia. Britannica Year Book of Science and the Future. Chicago: U.S.A, 1972.

MLA استشهاد

Britannica, Encyclopaedia. Britannica Year Book of Science and the Future. U.S.A, 1972.