Cita APA (7a ed.)
Helpman, E., & Krugman, P. R. (1993). Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition, and the International Economy (5. ed.). MIT Press.
Cita Chicago Style (17a ed.)
Helpman, Elhanan, y Paul R. Krugman. Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition, and the International Economy. 5. ed. Cambridge: MIT Press, 1993.
Cita MLA (9a ed.)
Helpman, Elhanan, y Paul R. Krugman. Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition, and the International Economy. 5. ed. MIT Press, 1993.
Precaución: Estas citas no son 100% exactas.