Cita APA (7th ed.)

Valdes, A., & Schaeffer, B. (1996). Surveillance of agricultural price and trade policies: A handbook for Paraguay. World Bank.

Cita Chicago (17th ed.)

Valdes, Alberto, i Barry Schaeffer. Surveillance of Agricultural Price and Trade Policies: A Handbook for Paraguay. Washington, D.C: World Bank, 1996.

Cita MLA (9th ed.)

Valdes, Alberto, i Barry Schaeffer. Surveillance of Agricultural Price and Trade Policies: A Handbook for Paraguay. World Bank, 1996.