Columbia subject headings:
Admission of nonimmigrants--United States.
Foreign workers certification--United States.
United States--Emigration and immigration.
United States. Immigration and Naturalization Service--Management.
Harvard subject headings:
Princeton subject headings:
Admission of nonimmigrants--United States.
Foreign workers certification--United States.
United States--Emigration and immigration.
United States. Immigration and Naturalization Service--Management.