Columbia subject headings:
Harvard subject headings:
Coal mines and mining--Japan--History.
Coal trade--Japan--History.
Conglomerate corporations--Japan--History.
Mitsui Kōzan Kabushiki Kaisha.
Princeton subject headings:
Coal mines and mining--Japan--History.
Coal trade--Japan--History.
Conglomerate corporations--Japan--History.
Mitsui Kōzan Kabushiki Kaisha.