Babbie, Earl <br/><br/>
The Practice of social research  [Texte imprimé] / 
Earl Babbie 
 - 7th ed. 
 - Belmont:  Wadsworth Publishing,  1995 
<br/><br/>Notes bibliogr. 
<br/><br/><label>ISBN: </label>0-534-18744-7 
<br/><br/><label>Dewey Class. No.: </label>300.72