Ellis, Norman R. <br/><br/>
Handbook of mental deficiency :  psychological theory and research / 
Norman R. Ellis. 
 - New York :  McGraw-Hill,  1963. 
 - xv, 722 p. :  ill. diagrs. ;  24 cm. 
<br/><br/>Includes bibliographies. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mental retardation