Gaya APA
Hakes, D, R.
(2004).
Principles of Economics 3rd Ed
(
3rd Ed)
.
United Stated of America:
Thomson South-Western.
Gaya MLA
Hakes, David, R.
"Principles of Economics 3rd Ed".
3rd Ed
United Stated of America:
Thomson South-Western,
2004.
Text.