APA (7th ed.) Zitazioa

Helpman, E. (2011). Understanding global trade. Belknap Press of Harvard University Press.

Chicago Style (17th ed.) Zitazioa

Helpman, Elhanan. Understanding Global Trade. Cambridge, Mass.: Belknap Press of Harvard University Press, 2011.

MLA (9th ed.) Zitazioa

Helpman, Elhanan. Understanding Global Trade. Belknap Press of Harvard University Press, 2011.