Columbia subject headings:
Bulgaria--Relations--Russia.
Russia--Relations--Bulgaria.
Stoletov, Nikolaĭ Grigorʹevich, 1834-1912.
Harvard subject headings:
Bulgaria--Relations--Russia.
Russia--Relations--Bulgaria.
Stoletov, Nikolaĭ Grigor'evich, 1834-1912.
Princeton subject headings:
Bulgaria--Relations--Russia.
Russia--Relations--Bulgaria.
Stoletov, Nikolaĭ Grigorʹevich, 1834-1912.