Columbia subject headings:
Harvard subject headings:
Anesthesiology--Germany--History--20th century.
Chronic pain--Diagnosis--Germany--History--20th century.
Chronic pain--Treatment--Germany--History--20th century.
Pain--Treatment--Germany--History--20th century.
Princeton subject headings:
Anesthesiology--Germany--History--20th century.
Chronic pain--Diagnosis--Germany--History--20th century.
Chronic pain--Treatment--Germany--History--20th century.
Pain--Treatment--Germany--History--20th century.