Columbia subject headings:
Atheism--Soviet Union.
Religious thought--Russia--19th century.
Religious thought--Soviet Union.
Harvard subject headings:
Atheism--Soviet Union.
Religious thought--Russia--19th century.
Religious thought--Soviet Union--19th century.
Religious thought--Soviet Union--20th century.
Religious thought--Soviet Union.
Princeton subject headings:
Atheism--Soviet Union.
Religious thought--Russia--19th century.
Religious thought--Soviet Union.