Columbia subject headings:
Philosophy, German--19th century.
Philosophy, German--20th century.
Philosophy, Russian--19th century.
Philosophy, Russian--20th century.
Harvard subject headings:
Philosophy, German--19th century.
Philosophy, German--20th century.
Philosophy, Russian--19th century.
Philosophy, Russian--20th century.
Princeton subject headings:
Philosophy, German--19th century.
Philosophy, German--20th century.
Philosophy, Russian--19th century.
Philosophy, Russian--20th century.