Vockell, Edward L. And Asher, J. William <br/><br/>
Educational Research 

 - 2nd Ed 
 - Merrill, Columbus  1995 
 - xvi, 489 
<br/><br/><label>ISBN: </label>0-02-423105-3 
<br/><br/><label>Dewey Class. No.: </label>370.78 Voc /Ash