Gaya APA
Krugman, ., Obsfeld, . (2009).
International economics; Theory dan Policy (Ed.8).
Boston:
Pearson Addison Wesley.
Gaya MLA
Krugman, ., Obsfeld, .
"International economics; Theory dan Policy".
Ed.8
Boston:
Pearson Addison Wesley,
2009.
Textbook.