Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.