Cooper, K. (2019). The contact paradox: Challenging our assumptions in the search for extraterrestrial intelligence. Bloomsbury Sigma.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCooper, Keith. The Contact Paradox: Challenging Our Assumptions in the Search for Extraterrestrial Intelligence. London: Bloomsbury Sigma, 2019.
एमएलए (8वां संस्करण) प्रशस्ति पत्रCooper, Keith. The Contact Paradox: Challenging Our Assumptions in the Search for Extraterrestrial Intelligence. Bloomsbury Sigma, 2019.
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