Lacy, Edward A. <br/><br/>
The black opal 
Victoria Holt 
 - New Jersey  Prentice-Hall  c1977 
 - xiv,269p.:  ill.;  23cm 
<br/><br/>Includes bibliographies 
<br/><br/><label>ISBN: </label>0133773418 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Electronic industries-safety measures<br/>Electronics-safety measures