Sommer, A. H <br/><br/>
Photoelectric tubes 
A. H. Sommer 
 - London  Methuen  1951 
 - viii, 118p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Electronics<br/>NASA Thesaurus<br/>Photoelectric Tubes
<br/><br/><label>Universal Decimal Class. No.: </label>621.383  / SOM