Birth order and mental ability.  [electronic resource] 

 -  Lancet (London, England)  Jun 1969 
 - 1301 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0140-6736 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Achievement<br/>Birth Order<br/>Humans<br/>Intelligence<br/>Intelligence Tests<br/>Only Child