Coles, P., & Ellis, G. (1997). Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge University Press.
Chicago-čujuhus (17. p.)Coles, Peter, juo George Ellis. Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge, United Kingdom: Cambridge University Press, 1997.
MLA-čujuhus (9. p.)Coles, Peter, juo George Ellis. Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge University Press, 1997.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.