Columbia subject headings:
Hapgood, Hutchins, 1869-1944.
Hapgood, Norman, 1868-1937.
Hapgood, William Powers.
Intellectuals--United States--Biography.
Social reformers--United States--Biography.
Harvard subject headings:
Hapgood, Hutchins, 1869-1944.
Hapgood, Norman, 1868-1937.
Hapgood, William Powers.
Intellectuals--United States--Biography.
Social reformers--United States--Biography
Princeton subject headings: