Columbia subject headings:
Ermakov family.
Krenino (Russia)--History.
Levykin family.
Levykino (Russia)--History.
Ushakogo (Russia)--History.
Ushakov family.
Harvard subject headings:
Levykin, K. G.
Mt︠s︡enskiĭ raĭon (Russia)--Genealogy.
Mt︠s︡enskiĭ raĭon (Russia)--History, Local.
Princeton subject headings: