Ehlers Walter H., Krishef Curtis H., Prothero Jon C. <br/><br/>
Introduction to mental retardation  a programmed text 

 - 2nd ed. 
 - Columbus  Charles E. Merrill Publishing  1973 
 - 384 p.  25 cm. 
 -   .
<br/><br/>  
<br/><br/>  Mental Retardation 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mental Retardation
<br/><br/><label>Dewey Class. No.: </label>WM300  / EHL