CENOV, A. (1975) “Forecasting the development and the territorial distribution of health services in the People's Republic of Bulgaria,” pp. 81–95 in N.T.J. Bailey and M. Thompson (eds.) Systems Aspects of Health Planning. Amsterdam: North-Holland.
2.
POPOV, G. A. (1961) Principles of Health Planning in the USSR. Geneva: World Health Organization.
3.
Statisticheski Godishnik (Annual) Sofia: Ministerstvo na Informatsiyata i Suobshteni-yata.
4.
Területi Idösorok, 1965-1974 (1976) Budapest: Központi Statisztikai Hivatal.
5.
Területi Statisztikai Évkönyv (Annual) Budapest: Központi Statisztikai Hivatal.
6.
WELSH, W. A. (1997) “Interregional variatios in public goods and services: some methodological issues and a preliminary analysis.”Jahrbuch der Wirtschaft Osteuropas7: 171–212.