Petroleum industry and trade History 41 Political aspects 38 Politics and government 25 Government policy 24 Energy policy 23 Gas industry 21 more ... Economic aspects 15 Environmental aspects 14 Petroleum 14 Petroleum reserves 14 Foreign relations 13 Petroleum engineering 12 Social aspects 12 Economic conditions 11 Petroleum products 11 Prices 11 Econometric models 10 Foreign economic relations 9 Social conditions 9 Energy consumption 8 Fiscal policy 7 Economic development 5 Management 5 Renewable energy sources 5 Balance of payments 4 Economic policy 4 Energy industries 4 Indians of South America 4 Natural gas 4 less ...