V Economics > V.12 Environmental and resource economics > V.12.02 Energy economics > Energy sector > Gas industry

W Economic sectors > W.22 Public sector > Public utilities > Energy sector > Gas industry

W Economic sectors > W.04 Energy and Water Industries > W.04.01 Energy sector > Energy sector > Gas industry

W Economic sectors > W.04 Energy and Water Industries > W.04.01 Energy sector > Gas industry