Shepherd, G. S., & Futrell, G. A. (1969). Marketing farm products; economic analysis (5th ed.). Iowa State University Press.
Citazione stile Chigago Style (17a edizione)Shepherd, Geoffrey Seddon, e Gene A. Futrell. Marketing Farm Products; Economic Analysis. 5th ed. Ames: Iowa State University Press, 1969.
Citatione MLA (9a ed.)Shepherd, Geoffrey Seddon, e Gene A. Futrell. Marketing Farm Products; Economic Analysis. 5th ed. Iowa State University Press, 1969.