Cozby, P. C. (2004). Methods in behavioral research (8th ed.). McGraw- Hill.
Dyfyniad Arddull ChicagoCozby, Paul C. Methods in Behavioral Research. 8th ed. New York: McGraw- Hill, 2004.
Dyfyniad MLACozby, Paul C. Methods in Behavioral Research. 8th ed. McGraw- Hill, 2004.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.