APA Style
Gibbons, Gail.. (2001).
Polar bears .
:
Harpercollins.
Chicago Style
Gibbons, Gail..
Polar bears.
:
Harpercollins,
2001.
Text.
MLA Style
Gibbons, Gail..
Polar bears.
:
Harpercollins,
2001.
Text.
Turabian Style
Gibbons, Gail..
Polar bears.
:
Harpercollins,
2001.
Print.