Mental deficiency, the changing outlook / 
edited by Ann M. Clarke and A. D. B. Clarke. 
 - 3rd ed. 
 - London :  Methuen etc.,  1974. 
 - 886 p. :  ill. ;  24 cm. 
<br/><br/><label>ISBN: </label>0416807208 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mental retardation.