Young, R. G. e. (1969). 1970 Britannica yearbooks of science and the future. Encyclopaedia Britannica.
Chicago Edition CitationYoung, Richard G ed. 1970 Britannica Yearbooks of Science and the Future. Chicago: Encyclopaedia Britannica, 1969.
Cita MLAYoung, Richard G ed. 1970 Britannica Yearbooks of Science and the Future. Encyclopaedia Britannica, 1969.
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