Coles, P., & Ellis, G. (1997). Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge University Press.
Chicago Style (17. basım) AtıfColes, Peter, ve George Ellis. Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge, United Kingdom: Cambridge University Press, 1997.
MLA (9th ed.) AtıfColes, Peter, ve George Ellis. Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge University Press, 1997.
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