Columbia subject headings:
Bulgakov, Sergiĭ, 1871-1944--Political and social views.
Christian socialism--Russia.
Communism--Russia--History.
Idealism, Russian--History.
Idealism.
Philosophy, Russian--19th century.
Philosophy, Russian--20th century.
Russia--Intellectual life--1801-1917.
Struve, Petr Berngardovich, 1870-1944--Political and social views.
Harvard subject headings:
Bulgakov, Sergiĭ, 1871-1944--Political and social views.
Christian socialism--Russia--History.
Philosophy, Russian--19th century.
Philosophy, Russian--20th century.
Philosophy, Russian--Periodicals--Indexes.
Struve, Petr Berngardovich, 1870-1944--Political and social views.
Princeton subject headings:
Bulgakov, Sergiĭ, 1871-1944--Political and social views.
Christian socialism--Russia.
Communism--Russia--History.
Idealism, Russian--History.
Idealism.
Philosophy, Russian--19th century.
Philosophy, Russian--20th century.
Russia--Intellectual life--1801-1917.
Struve, Petr Berngardovich, 1870-1944--Political and social views.