Read, Peter G. <br/><br/>
Gemmological instruments: Their use and principles of operation 

 - 2nd Edition 
 - London  Butter Worths  1983 
 - 328p. 
<br/><br/><label>ISBN: </label> UKP 24.00 
<br/><br/><label>Source: </label> UKP 24.00 
<br/><br/><label>Dewey Class. No.: </label>549.1 REA