Smith, Sydney F <br/><br/>
Telephony & telegraphy A  an introduction to telephone and telegraph instruments and exchanges, 
by Sydney F. Smith 
 - 2d ed. 
 - London,  Oxford U.P.  c1974 
 - xv, 282 p.  illus.  25 cm 
<br/><br/> Third ed. published in 1978 under title: Telephony and telegraphy 
<br/><br/>Bibliography: p. [260] 
<br/><br/><label>ISBN: </label>0198593449 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telegraph<br/>Telephone