Blalock, H. M. (1972). Casual inferences in nonexperimental research. Norton.
Dyfyniad Arddull ChicagoBlalock, Hubert M. Casual Inferences in Nonexperimental Research. New York: Norton, 1972.
Dyfyniad MLABlalock, Hubert M. Casual Inferences in Nonexperimental Research. Norton, 1972.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.