Cita APA (7a ed.)

Helpman, E., & Krugman, P. R. (1985). Market structure and foreign trade: Increasing returns, imperfect competition, and the international economy. 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. Cambridge, Mass.: MIT Press, 1985.

Cita MLA (9a ed.)

Helpman, Elhanan, y Paul R. Krugman. Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition, and the International Economy. MIT Press, 1985.