Columbia subject headings:
Harvard subject headings:
Christiansen, Broder, 1869-1958.
Civilization, Modern
Philosophy, German--19th century.
Philosophy, German--20th century.
Self-control
Self-management (Psychology)
Princeton subject headings:
Christiansen, Broder, 1869-1958.
Civilization, Modern.
Philosophy, German--19th century.
Philosophy, German--20th century.
Self-control.
Self-management (Psychology)