Mitchell, M. L., & Jolley, J. M. (1992). Research design explained (2nd ed.). Harcourt Brace Jovanich.
Dyfyniad Arddull ChicagoMitchell, Mark L., and Janina M. Jolley. Research Design Explained. 2nd ed. Fort Worth, TX: Harcourt Brace Jovanich, 1992.
Dyfyniad MLAMitchell, Mark L., and Janina M. Jolley. Research Design Explained. 2nd ed. Harcourt Brace Jovanich, 1992.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.