Columbia subject headings:
Hydrology--Ethiopia.
Hydrology--Great Rift Valley.
Lakes--Ethiopia.
Lakes--Great Rift Valley.
Harvard subject headings:
Hydrology--Ethiopia.
Hydrology--Great Rift Valley.
Lakes--Ethiopia
Lakes--Great Rift Valley.
Princeton subject headings:
Hydrology--Ethiopia.
Hydrology--Great Rift Valley.
Lakes--Ethiopia.
Lakes--Great Rift Valley.