Columbia subject headings:
Harvard subject headings:
Cardiology--Research--Germany--Kiel--History--20th century.
Cardiology--Research--Maryland--Baltimore--History--20th century.
Cardiology--Study and teaching--Germany--Kiel--History--20th century.
Cardiology--Study and teaching--Maryland--Baltimore--History--20th century.
Johns Hopkins Hospital--History.
Princeton subject headings:
Cardiology--Research--Germany--Kiel--History--20th century.
Cardiology--Research--Maryland--Baltimore--History--20th century.
Cardiology--Study and teaching--Germany--Kiel--History--20th century.
Cardiology--Study and teaching--Maryland--Baltimore--History--20th century.
Johns Hopkins Hospital--History.