Columbia subject headings:
Harvard subject headings:
Bri͡ant͡sev, N. I͡A. (Nikolaĭ I͡Akovlevich), 1889-1937--Correspondence.
Florenskiĭ, P. A. (Pavel Aleksandrovich), 1882-1937--Correspondence.
Litvinov, R. N. (Roman Nikolaevich), 1890-1937--Correspondence.
Political persecution--Soviet Union.
Solovet͡skiĭ lagerʹ osobogo naznachenii͡a--History.
Soviet Union--History--1925-1953.
Vangengeĭm, Alekseĭ Feodosʹevich, 1881-1937--Correspondence.
Princeton subject headings:
Political prisoners--Soviet Union--Correspondence.
Political prisoners--Soviet Union--History--Sources.
Solovet︠s︡kiĭ lagerʹ osobogo naznachenii︠a︡--History--Sources.