Van Dale, Deobold B. <br/><br/>
Understanding educational research  : an introduction 

 - 4th ed. 
 - New York  McGraw-Hill Companies, Inc.  1979 
 - 547 
<br/><br/><label>ISBN: </label>0070668833 
<br/><br/><label>Dewey Class. No.: </label>CIR 001.4 V26u 1979