Yule William/ <br/><br/>
BEHAVIOUR MODIFICATON FOR THE MENTALLY HANDICAPPED.; 
William Yule/ 
 - Northe America  University Park Press  c1980 
 - 298P  Illu. 
<br/><br/> includes Appendix,References and index. 
<br/><br/><label>ISBN: </label>0839117469 
<br/><br/><label>Dewey Class. No.: </label>362.783