APA Style
Grego, Peter. (2006).
The Universe .
:
Harper Collins Publishers.
Chicago Style
Grego, Peter.
The Universe.
:
Harper Collins Publishers,
2006.
Text.
MLA Style
Grego, Peter.
The Universe.
:
Harper Collins Publishers,
2006.
Text.
Turabian Style
Grego, Peter.
The Universe.
:
Harper Collins Publishers,
2006.
Print.