Columbia subject headings:
Border security--Technological innovations--United States--Evaluation.
Electronic surveillance--United States--Evaluation.
Government purchasing--United States--Auditing.
Public contracts--United States--Management.
Harvard subject headings:
Border security--Technological innovations--United States--Evaluation.
Electronic surveillance--United States--Evaluation.
Government purchasing--United States--Auditing.
Public contracts--United States--Management.
Princeton subject headings:
Border security--Technological innovations--United States--Evaluation.
Electronic surveillance--United States--Evaluation.
Government purchasing--United States--Auditing.
Public contracts--United States--Management.