Round, H J. <br/><br/>
Shielded four electrode valve : 

 - London :  Cassell and Company,  1927. 
 - vii, 88 p. :  ill. ;  18 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Vacuum Tubes<br/>Electron Flow<br/>Valve Circuit Design
<br/><br/><label>Dewey Class. No.: </label>621.384  / ROU