Mercer, G. Lawrence <br/><br/>
Security systems and equipment/2e 

 - 2nd ed. 
 - London  Macdonald and Evans  1964 
 - 39p. 
<br/><br/><label>Subjects--Index Terms: </label>Security systems 
<br/><br/><label>Dewey Class. No.: </label>658  /  MER