Columbia subject headings:
Klages, Ludwig, 1872-1956.
Lessing, Theodor, 1872-1933.
Harvard subject headings:
Klages, Ludwig, 1872-1956.
Lessing, Theodor, 1872-1933.
Princeton subject headings:
Klages, Ludwig, 1872-1956.
Lessing, Theodor, 1872-1933.