Cita APA (7th ed.)

Sapsford, D., & Winters, L. A. (1990). Primary commodity prices: Economic models and policy. Cambridge University Press.

Cita Chicago (17th ed.)

Sapsford, David, i L. Alan Winters. Primary Commodity Prices: Economic Models and Policy. Cambridge: Cambridge University Press, 1990.

Cita MLA (9th ed.)

Sapsford, David, i L. Alan Winters. Primary Commodity Prices: Economic Models and Policy. Cambridge University Press, 1990.