Lehnert, Joseph <br/><br/>
Introduction to telegraph engineering/ 
Joseph Lehnert 
 - Berlin:  Siemons,  1969 
 - 155 p.;  21 cm. 
<br/><br/><label>ISBN: </label> £ 3.10 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telegraph<br/>Telegraph--Equipment and supplies<br/>Telegraph--Operator manuals
<br/><br/><label>Dewey Class. No.: </label>621.382