Thorn, Samuel A. <br/><br/>
Let's know now / 
Samuel A. Thorn and Carl D. Duncan. 
 - Chicago :  Benefic press,  c 1961. 
 - 280 p. :  ill. ;  20 cm. 
 - Science and conservation. .
<br/><br/> Included index. 
<br/><br/>300  300 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science.
<br/><br/><label>Dewey Class. No.: </label>500 / T343l