Technical instruction on the fitting of signal office instrument rooms  / 
Telegraph Engineering, Post and Telegraphs, India 
 - 2nd rev.enl. ed 
 - Calcutta :  Superintendent Govt. Printing  1921 
 - 25 p. ;  ill . ;  32 cm. 
<br/><br/><label>Dewey Class. No.: </label>621.383