Research Methods for Social Workers  
Bonnie L. Yegidis , Robert W. Weibanch 
 - 6th ed. 
 - Boston:  Pearson,  2009. 
 - xvi,351 p,: 
<br/><br/><label>ISBN: </label>9780205585588 
<br/><br/><label>LC Class. No.: </label>HV11  / .Y43 2009