Citazione Stile APA (7a Edizione)

Coles, P., & Ellis, G. (1997). Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge University Press.

Citazione stile Chigago Style (17a edizione)

Coles, Peter, e George Ellis. Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge, United Kingdom: Cambridge University Press, 1997.

Citatione MLA (9a ed.)

Coles, Peter, e George Ellis. Is the Universe Open or Closed?: The Density of Matter in the Universe. Cambridge University Press, 1997.