Babbie, Earl <br/><br/>
The basics of social research / 
Earl Babbie 
 - 4th ed. 
 - Belmont :  Cengage Learning,  2007 
 - xxiv, 550 p. :  ill. ;  24 cm. 
<br/><br/><label>ISBN: </label>0495102334 9780495102335 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Social sciences--Research<br/>Social sciences--Methodology