Gaya APA
Principles Of Economics. (2007).
New York:
[s.n.].
Gaya Chicago
Principles Of Economics.
.
New York:
[s.n.],
2007.
Text.
Gaya MLA
Principles Of Economics.
.
New York:
[s.n.],
2007.
Text.
Gaya Turabian
Principles Of Economics.
New York:
[s.n.],
2007.
Print.