Hausmann, Erich. <br/><br/>
Telegraph engineering /  
by Erich Haussmann 
 - New York :   D. Van Nostrand Company,   1915. 
 - 386 p. : il., foto. ; 24 cm. 
<br/><br/> Apéndice 388-395 p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>TELEGRAFIA
<br/><br/><label>Universal Decimal Class. No.: </label>621.394