Cita APA (7a ed.)

Helpman, E. (1988). Growth, technological progress, and trade. [s.n.].

Cita Chicago Style (17a ed.)

Helpman, Elhanan. Growth, Technological Progress, and Trade. [S.l.]: [s.n.], 1988.

Cita MLA (9a ed.)

Helpman, Elhanan. Growth, Technological Progress, and Trade. [s.n.], 1988.