Gaya APA
Samuelson, P, A., NORDHAUS, W, D.
(2005).
ECONOMICS, 18 ED.
(
18)
.
:
.
Gaya MLA
Samuelson, Paul, A.., NORDHAUS, WILLIAM, D..
"ECONOMICS, 18 ED.".
18
:
,
2005.
Buku.