"Proton",  pseud. <br/><br/>
Switchboard instruments;  a practical work for installation engineers, contractors, plant engineers and works electricians /  
by "Proton."  General editor: E. Molloy 
 - Brooklyn, N.Y. :  Chemical publishing co., inc.,  1941. 
 - viii, 183 p.  illus., diagrs.  23 cm. 
 - Electrical engineer series-v. 9 .
<br/><br/> With 135 diagrams and photographs. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>ELECTRICIDAD<br/>CONTADORES ELECTRICOS
<br/><br/><label>Universal Decimal Class. No.: </label>621.3