Columbia subject headings:
Harvard subject headings:
Niger River Delta (Nigeria)--Economic conditions--Congresses.
Niger River Delta (Nigeria)--Politics and government--Congresses.
Niger River Delta (Nigeria)--Social conditions--Congresses.
Petroleum industry and trade--Political aspects--Nigeria--Niger River Delta--Congresses.
Princeton subject headings:
Niger River Delta (Nigeria)--Economic conditions--Congresses.
Niger River Delta (Nigeria)--Politics and government--Congresses.
Niger River Delta (Nigeria)--Social conditions--Congresses.
Petroleum industry and trade--Political aspects--Nigeria--Niger River Delta.