Langbein Laura Irwin <br/><br/>
Discovering whether programs work   A guide to statistical methods for program evaluation 
Langbein Laura Irwin 
 - Santa  Monica Goodyear Publishing Company      1980 
<br/><br/><label>Standard No.: </label>235,058 
<br/><br/><label>Source: </label> Textual 
<br/><br/><label>Dewey Class. No.: </label>Sigma:(B28)g, M0