Columbia subject headings:
Duun, Olav, 1876-1939. Medmenneske-Trilogie.
Harvard subject headings:
Duun, Olav, 1876-1939. Medmenneske-Trilogie.
Princeton subject headings:
Duun, Olav, 1876-1939. Medmenneske.
Duun, Olav, 1876-1939. Ragnhild.
Duun, Olav, 1876-1939. Siste leveåre.