Columbia subject headings:
Gas fields--Black Sea Region--Maps.
Gas fields--Caspian Sea Region--Maps.
Maps.
Natural gas pipelines--Black Sea Region--Maps.
Natural gas pipelines--Caspian Sea Region--Maps.
Oil and gas leases--Black Sea Region--Maps.
Oil and gas leases--Caspian Sea Region--Maps.
Oil fields--Black Sea Region--Maps.
Oil fields--Caspian Sea Region--Maps.
Petroleum pipelines--Black Sea Region--Maps.
Petroleum pipelines--Caspian Sea Region--Maps.
Harvard subject headings:
Gas fields--Black Sea Region--Maps.
Gas fields--Caspian Sea Region--Maps.
Natural gas pipelines--Black Sea Region--Maps.
Natural gas pipelines--Caspian Sea Region--Maps.
Oil and gas leases--Black Sea Region--Maps.
Oil and gas leases--Caspian Sea Region--Maps.
Oil fields--Black Sea Region--Maps.
Oil fields--Caspian Sea Region--Maps.
Petroleum pipelines--Black Sea Region--Maps.
Petroleum pipelines--Caspian Sea Region--Maps.
Princeton subject headings:
Black Sea--Maps.
Caspian Sea--Maps.
Caucasus--Maps.
Caucasus.
Gas fields--Black Sea Region--Maps.
Gas fields--Caspian Sea Region--Maps.
Gas fields--Caucasus--Maps.
Maps.
Natural gas pipelines--Black Sea Region--Maps.
Natural gas pipelines--Caspian Sea Region--Maps.
Oil and gas leases--Black Sea Region--Maps.
Oil and gas leases--Caspian Sea Region--Maps.
Oil fields--Black Sea Region--Maps.
Oil fields--Caspian Sea Region--Maps.
Oil fields--Caucasus--Maps.
Petroleum pipelines--Black Sea Region--Maps.
Petroleum pipelines--Caspian Sea Region--Maps.
Petroleum pipelines--Caucasus--Maps.