Grossman, G. M., & Helpman, E. (2002). Interest groups and trade policy. Princeton University Press.
Lua i Stíl Chicago (17ú heag.)Grossman, Gene M., agus Elhanan Helpman. Interest Groups and Trade Policy. Princeton, N.J: Princeton University Press, 2002.
Lua MLA (9ú heag.)Grossman, Gene M., agus Elhanan Helpman. Interest Groups and Trade Policy. Princeton University Press, 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.