Everyman's encyclopedia  bulgaria-coal-fields 
edited by Athelstan Ridgway 
 - 3rd ed. 
 - London  J.M. Dent & sons ltd.  1950 
 - 758p.  v.3 
<br/><br/><label>ISBN: </label> [] 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Encyclopedia
<br/><br/><label>Dewey Class. No.: </label>030  / RID