Spangenberg Karl R <br/><br/>
Vacum tubes 

 -  1948 
 - p.  cm. 
<br/><br/><label>Standard No.: </label>71696 
<br/><br/><label>Source: </label> Textual 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Electrical engineering
<br/><br/><label>Dewey Class. No.: </label>D666:33, H8;1