Columbia subject headings:
Labor mobility--Puerto Rico.
Puerto Ricans--Employment--United States.
Puerto Rico--Emigration and immigration.
Harvard subject headings:
Labor mobility--Puerto Rico.
Puerto Ricans--Employment--United States.
Puerto Rico--Emigration and immigration.
Princeton subject headings:
Labor mobility--Puerto Rico.
Puerto Ricans--Employment--United States.
Puerto Rico--Emigration and immigration.