Columbia subject headings:
Harvard subject headings:
Carbones de Colombia S.A.
Coal mines and mining--Colombia--Ejón Hill Region.
Coal trade--Colombia--Ejón Hill Region.
International Colombia Resources Corporation.
Princeton subject headings:
Carbones de Colombia S.A.
Coal mines and mining--Colombia--Ejón Hill Region.
Coal trade--Colombia--Ejón Hill Region.
International Colombia Resources Corporation.