Columbia subject headings:
Harvard subject headings:
Germany--Biography.
Hellpach, Willy, 1877-1955.
Historians--Germany--Biography
Psychologists--Germany--Biography
Sociologists--Germany--Biography.
Princeton subject headings:
Hellpach, Willy Hugo, 1877-1955.
Hellpach, Willy, 1877-1955--Bibliography.
Psychologists--Germany--Biography.