Crotty,, M. (1998). Foundations of social research (1st.). Sage.
Dyfyniad Arddull ChicagoCrotty,, Michael. Foundations of Social Research. 1st. London: Sage, 1998.
Dyfyniad MLACrotty,, Michael. Foundations of Social Research. 1st. Sage, 1998.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.