Calculated from the results of the 2001 Bulgarian census for the administrative regions of Dobrich and Silistra, from "Население към 01.03.2001 г. по области и етническа група" (in Bulgarian). Националния статистически институт. Retrieved 2007-05-02.
censusresults.nsi.bg
Calculated from the results of the 2011 Bulgarian census for the administrative regions of Dobrich and Silistra, from "Население по етническа група и майчин език" (in Bulgarian). Националния статистически институт. Retrieved 2015-11-20.
worldcat.org
Calculated from results of the 1930 census per county, taken from Mănuilă, Sabin (1939). La Population de la Dobroudja (in French). Bucarest: Institut Central de Statistique. OCLC1983592.
