Gaya APA
Samuelson, P, A., Nordhaus, W, D.
(1987).
Economics Ed. 12
(
Ke-12)
.
Singapore:
McGraw Hill.
Gaya MLA
Samuelson, Paul, A., Nordhaus, William, D.
"Economics Ed. 12".
Ke-12
Singapore:
McGraw Hill,
1987.
Text.