Mittler, Peter J <br/><br/>
The study of twins 
/ by Peter Mittler 
 - Harmondsworth  Penguin  1971 
 - 192 p; illus. 19 cm. 
<br/><br/>Bibliography: p. 172-186. 
<br/><br/><label>ISBN: </label>014080210X 
<br/><br/><label>LCCN: </label>73-501665 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Twins