Não informado. (1968). Astrophysics and Space Science: An international journal of cosmic physics. D. Reidel Publishing.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Astrophysics and Space Science: An International Journal of Cosmic Physics. Dordrecht, Holanda: D. Reidel Publishing, 1968.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Astrophysics and Space Science: An International Journal of Cosmic Physics. D. Reidel Publishing, 1968.
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