CRAWLEY,CHETWODE <br/><br/>
FROM TELEGRAPHY TO TELEVISION  THE STORY OF ELECTRICAL COOMUNICATIONS 
CHETWODE CRAWLEY 
 - LONDON  FREDERICK WARNE &CO.LTD  1931 
 - 212 
<br/><br/> PE mean Physics, Electricity and Magnetism Page 450-456 in A to Z Register (Acc. No. Pe1-Pe205) 
<br/><br/><label>Dewey Class. No.: </label>PE84