APA Citatie

Coles, P., & Ellis, G. F. R. (1997). Is the universe open or closed? Cambridge University Press.

Chicago Style citaat

Coles, Peter, en George Francis Rayner Ellis. Is the Universe Open or Closed? Cambridge: Cambridge University Press, 1997.

MLA citatie

Coles, Peter, en George Francis Rayner Ellis. Is the Universe Open or Closed? Cambridge University Press, 1997.