Columbia subject headings:
Border patrols--Minnesota.
Emergency management--Minnesota.
Ports of entry--Security measures--Minnesota.
Terrorism--Minnesota--Prevention.
Harvard subject headings:
Border patrols--Minnesota.
Border security--Minnesota.
Emergency management--Minnesota.
Ports of entry--Security measures--Minnesota.
Terrorism--Minnesota--Prevention.
Princeton subject headings:
Border patrols--Minnesota.
Emergency management--Minnesota.
Ports of entry--Security measures--Minnesota.
Terrorism--Minnesota--Prevention.