Columbia subject headings:
National security--United States--Evaluation.
Terrorism--United States--Prevention.
United States. Dept. of Homeland Security--Evaluation.
Harvard subject headings:
National security--United States--Evaluation.
Terrorism--United States--Prevention
United States. Department of Homeland Security--Evaluation.
Princeton subject headings:
National security--United States--Evaluation.
Terrorism--United States--Prevention.
United States. Department of Homeland Security--Evaluation.