Petroleum industry and trade History 217 Political aspects 182 Energy policy 118 Politics and government 100 Environmental aspects 97 Government policy 96 més ... Petroleum 87 Economic conditions 76 Foreign relations 75 Gas industry 68 Petroleum reserves 54 Social aspects 54 Economic aspects 52 Prices 47 Petroleum products 45 Social conditions 44 Foreign economic relations 36 Petroleum engineering 34 Energy consumption 33 Power resources 27 World politics 27 Economic policy 24 Forecasting 22 Petroleum law and legislation 20 Economic development 19 Environmental conditions 19 Natural resources 18 Energy industries 17 Geopolitics 17 menys ...