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Sampling : an introduction for social scientists
Conway, Freda, (1967)
Microcensus sample surveys
Schubnell, Hermann, (1969)
Sample survey methods and theory
Hansen, Morris H., (1953)
Sampling techniques
Cochran, William G., (1953)
Experimental designs
Cochran, William G., (1956)
Statistical methods : applied to experiments in agriculture and biology
Snedecor, George W., (1964)