Hubert Blaclock M. A. B. B., . (1968). Methodology in social research. : Mcgraw hill.
Hubert Blaclock M Ann Blalock B, . 1968. Methodology in social research. : Mcgraw hill.
Hubert Blaclock M Ann Blalock B, . Methodology in social research. : Mcgraw hill. 1968.