Columbia subject headings:
Harvard subject headings:
Presidents--United States--Biography
Presidents--United States--History--20th century
Presidents--United States--History--21st century.
United States--Politics and government--20th century
United States--Politics and government--21st century.
Princeton subject headings:
Presidents--United States--Biography.
Presidents--United States--History--20th century.
Presidents--United States--History--21st century.
United States--Politics and government--20th century.
United States--Politics and government--21st century.