Valentine, Charles Wilfred. <br/><br/>
The psychology of early childhood :  a study of mental development in the first years of life. 

 - [4th ed.]. 
 - London :  Methuen,  [1950] 
<br/><br/>Bibliographical footnotes. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Child study.<br/>Infants.