APA ציטוט

Krugman, P. (1991). Geography and trade. Leuven, Belgium: Leuven University Press.

Trích dẫn kiểu Chicago

Krugman, Paul. Geography and Trade. Leuven, Belgium: Leuven University Press, 1991.

ציטוט MLA

Krugman, Paul. Geography and Trade. Leuven, Belgium: Leuven University Press, 1991.