Columbia subject headings:
Huahe, Mao.
Oil fields--China--History.
Petroleum industry and trade--China--Daqing (Heilongjiang Sheng)
Petroleum industry and trade--China--History.
Petroleum industry and trade--Political aspects--China.
Harvard subject headings:
Mao, Huahe
Oil fields--China--History.
Petroleum industry and trade--China--Daqing (Heilongjiang Sheng)
Petroleum industry and trade--China--History.
Petroleum industry and trade--Political aspects--China.
Princeton subject headings: