एपीए उद्धरण

(1970). 1971 Britannica yearbooks of science and the future. Encyclopaedia Britannica.

शिकागो स्टाइल उद्धरण

1971 Britannica Yearbooks of Science and the Future. Chicago: Encyclopaedia Britannica, 1970.

एमएलए उद्धरण

1971 Britannica Yearbooks of Science and the Future. Encyclopaedia Britannica, 1970.