Ovcharov, Nikolay. <br/><br/>
Medieval Bulgarian empire / 
Nikolay Ovcharov. 
 - Plovdiv :  Lettera Publishers,  2006. 
 - 170 p. :  color illustrations, maps ;   30 cm. 
 - 91(497.2) (NLA) .
<br/><br/><label>ISBN: </label>9545166371 
<br/><br/><label>Subjects--Topical Terms: </label><br/>History  --Bulgaria--681-1018 
<br/><br/><label>Universal Decimal Class. No.: </label>91(497.2) (NLA)