etymology: named after the Saint Sofia Church in the city, elements of which day back on the 4th century A.D. B? N?i v? ??c tính m?t s? l??ng l?n (t? 600.000 t?i 750.000) ng??i Roma t?i Bulgaria; g?n m?t n?a ng??i Roma truy?n th?ng t? xác ??nh mình v? s?c t?c là ng??i