Columbia subject headings:
Gross national product--Bulgaria--Statistics.
National income--Bulgaria--Accounting.
National income--Bulgaria--Statistics.
Harvard subject headings:
Gross national product--Bulgaria--Statistics.
National income--Bulgaria--Accounting.
National income--Bulgaria--Statistics.
National income--Bulgaria.
Princeton subject headings:
Gross national product--Bulgaria--Statistics.
National income--Bulgaria--Accounting.
National income--Bulgaria--Statistics.