Shepherd, G. S., & Futrell, G. A. (1969). Marketing farm products; economic analysis (5th ed.). Iowa State University Press.
Chicago-referens (17:e uppl.)Shepherd, Geoffrey Seddon, och Gene A. Futrell. Marketing Farm Products; Economic Analysis. 5th ed. Ames: Iowa State University Press, 1969.
MLA-referens (9:e uppl.)Shepherd, Geoffrey Seddon, och Gene A. Futrell. Marketing Farm Products; Economic Analysis. 5th ed. Iowa State University Press, 1969.