एपीए उद्धरण

Britannica, E. (1981). Britannica year book of science and the future. U.S.A.

शिकागो स्टाइल उद्धरण

Britannica, Encyclopaedia. Britannica Year Book of Science and the Future. Chicago: U.S.A, 1981.

एमएलए उद्धरण

Britannica, Encyclopaedia. Britannica Year Book of Science and the Future. U.S.A, 1981.