Columbia subject headings:
Castles--Russia (Federation)--History.
Fortification--Russia (Federation)--History.
Fortress-churches--Russia (Federation)--History.
Orthodox Eastern monasteries--Russia--History.
Harvard subject headings:
Castles--Russia--History.
Fortification--Russia--History.
Fortress-churches--Russia--History.
Military architecture--Russia--History.
Orthodox Eastern monasteries--Russia--History.
Princeton subject headings: