APA Style
Ferguson, Robert. (2009).
The Vikings: A History .
:
Penguin Group.
Chicago Style
Ferguson, Robert.
The Vikings: A History.
:
Penguin Group,
2009.
Text.
MLA Style
Ferguson, Robert.
The Vikings: A History.
:
Penguin Group,
2009.
Text.
Turabian Style
Ferguson, Robert.
The Vikings: A History.
:
Penguin Group,
2009.
Print.