The practice of social research 
Babbie, Earl R. 
 - Fourth edition. 
 -  Wadsworth Pub. Co.,  1986 
 - xxii, 577 p. 
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<br/><br/><label>ISBN: </label>0-534-05658-X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Social sciences -- Methodology.
<br/><br/><label>Dewey Class. No.: </label>GS 300.72 B11p 1986