Columbia subject headings:
Aeronautics, Commercial--Security measures--United States--Finance.
United States. Transportation Security Administration--Appropriations and expenditures.
Harvard subject headings:
Aeronautics, Commercial--Security measures--United States--Finance.
United States. Transportation Security Administration--Appropriations and expenditures.
Princeton subject headings:
Aeronautics, Commercial--Security measures--United States--Finance.
United States. Transportation Security Administration--Appropriations and expenditures.