Columbia subject headings:
Efimenko, A. I︠A︡. (Aleksandra I︠A︡kovlevna), 1848-1919.
Efimenko, P. S. (Petr Savvich), 1835-1908.
Historians--Russia--Biography.
Historians--Ukraine--Biography.
Russia--Relations--Ukraine.
Ukraine--Relations--Russia.
Harvard subject headings:
Efimenko, A. I?A?. (Aleksandra I?A?kovlevna), 1848-1919.
Efimenko, P. S. (Petr Savvich), 1835-1908.
Historians--Russia--Biography
Historians--Ukraine--Biography
Russia--History.
Russia--Relations--Ukraine.
Ukraine--History.
Ukraine--Relations--Russia.
Princeton subject headings:
Efimenko, A. I︠A︡. (Aleksandra I︠A︡kovlevna), 1848-1919.
Efimenko, P. S. (Petr Savvich), 1835-1908.
Historians--Russia--Biography.
Historians--Ukraine--Biography.
Russia--Relations--Ukraine.
Ukraine--Relations--Russia.