Gaya APA
Krugman, P, R., Obstfeld, M. (2000).
International Economics : Theory and Policy (Edisi ke-5).
Amerika:
Addison Wesley.
Gaya MLA
Krugman, Paul, R., Obstfeld, Maurice.
"International Economics : Theory and Policy".
Edisi ke-5
Amerika:
Addison Wesley,
2000.
Textbook.