Pickford, Ralph William,    1903- <br/><br/>
Individual differences in colour vision /    
R. W. Pickford. 
 - London :   Routledge and Paul ,   1951. 
 - xviii, 386p. :    ill. ;    23cm. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Color-sense.--------
<br/><br/><label>Dewey Class. No.: </label>612.8433 PIC