Production of dress ornaments in the fortresses and small settlements in North Bulgaria during the period from the 5th till the 7th century ad - Haralambieva, Anna (The Roman and late Roman city. The International Conference (Veliko Turnovo 26-30 July 2000). Rimskijat i kăsnoantičnijat grad. Meždunarodna Naučna Konferencija (Veliko Tărnovo 26-30 juli 2000)., 2002)