Simpson, George Gaylord, 1902- <br/><br/>
Principles of animal taxonomy/ 
George Gaylord Simpson. 
 - New York:  Columbia University Press,  1961. 
 - 247 p. :  ill. ;  24 cm. 
 - Columbia biological series  no. 20 .
<br/><br/><label>LCCN: </label>60-13939 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Zoology--Classification