HATFIELD, H. STAFFORD  <br/><br/>
INVENTIONS AND THEIR USES IN SCIENCE TODAY 
H. STAFFORD HATFIELD 
 - NEW YORK   PENGUIN BOOKS LIMITED  1939 
 - 176 
<br/><br/> Rs mean Reading Circle Page 1250-1275 in A-Z Register (Acc. No. Rs1-Rs717)  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Reading Circle
<br/><br/><label>Dewey Class. No.: </label>RS33