Bracewell, R. N. 1. (1975). The Galactic club: Intelligent life in outer space. San Francisco: W. H. Freeman and Company.
Παραπομπή Chicago StyleBracewell, Ronald N. 1921-2007. The Galactic Club: Intelligent Life in Outer Space. San Francisco: W. H. Freeman and Company, 1975.
Παραπομπή MLABracewell, Ronald N. 1921-2007. The Galactic Club: Intelligent Life in Outer Space. San Francisco: W. H. Freeman and Company, 1975.
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