Green, P. E., & Tull, D. S. (1973). Research for markting decisions (2nd ed.). Prentice Hall.
Dyfyniad Arddull ChicagoGreen, Paul E., and Donald S. Tull. Research for Markting Decisions. 2nd ed. Prentice Hall, 1973.
Dyfyniad MLAGreen, Paul E., and Donald S. Tull. Research for Markting Decisions. 2nd ed. Prentice Hall, 1973.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.