Columbia subject headings:
Harvard subject headings:
Anthrax--Washington (D.C.)
Bioterrorism--Washington (D.C.)
Letter mail handling--Washington (D.C.)--Safety measures.
Postal service--Washington (D.C.)--Management--Evaluation.
Princeton subject headings:
Anthrax--Washington (D.C.).
Bioterrorism--Washington (D.C.).
Letter mail handling--Washington (D.C.)--Safety measures.
Postal service--Washington (D.C.)--Management--Evaluation.