Columbia subject headings:
Federal aid to research--United States.
Merchant marine--United States.
Shipbuilding--Technological innovations.
Shipping bounties and subsidies--United States.
Shipping--United States.
Harvard subject headings:
Merchant marine--United States
Shipbuilding--Technological innovations.
Shipping bounties and subsidies--United States.
Shipping--United States
Princeton subject headings:
Federal aid to research--United States.
Merchant marine--United States.
Shipbuilding--Technological innovations.
Shipping bounties and subsidies--United States.
Shipping--United States.