Build your own intercoms / 
B.P.B. Editorial Board 
 - New Delhi :   Business promotion bureau  c1980. 
 - 22 p :  ill. ;  22 cm. 
<br/><br/>
<br/><br/><br/>English. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Build 
<br/><br/><label>Dewey Class. No.: </label>621.3893/BPB