Columbia subject headings:
Capitalists and financiers--United States--Biography.
Ludwig, Daniel Keith, 1897-1992.
Merchant marine--United States--Biography.
Millionaires--United States--Biography.
Harvard subject headings:
Billionaires--United States--Biography.
Capitalists and financiers--United States--Biography
Ludwig, Daniel Keith, 1897-
Ludwig, Daniel Keith, 1897-1992.
Merchant marine--United States--Biography.
Millionaires--United States--Biography
Rich people--United States--Biography.
Princeton subject headings:
Capitalists and financiers--United States--Biography.
Ludwig, Daniel Keith, 1897-
Merchant marine--United States--Biography.
Millionaires--United States--Biography.