Jackson, T. (2019). Are we alone in the universe?: Theories about intelligent life on other planets (First edition.). Gareth Stevens Publishing.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रJackson, Tom. Are We Alone in the Universe?: Theories About Intelligent Life on Other Planets. First edition. New York, NY: Gareth Stevens Publishing, 2019.
एमएलए (8वां संस्करण) प्रशस्ति पत्रJackson, Tom. Are We Alone in the Universe?: Theories About Intelligent Life on Other Planets. First edition. Gareth Stevens Publishing, 2019.
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