Begun, S. J. <br/><br/>
Magnetic recording  

 - Thermionic products ltd.  London  1949 
 - 242p.  Table, fig. 
<br/><br/><label>Nat. Bib. No.: </label>2580 
<br/><br/><label>Universal Decimal Class. No.: </label>538.1  / BEG