Petroleum industry and trade History 198 Political aspects 165 Energy policy 105 Government policy 90 Politics and government 90 Environmental aspects 89 more ... Petroleum 83 Economic conditions 72 Foreign relations 65 Gas industry 63 Economic aspects 49 Petroleum reserves 49 Social aspects 49 Prices 44 Petroleum products 42 Social conditions 39 Foreign economic relations 35 Energy consumption 32 Petroleum engineering 32 World politics 25 Power resources 24 Economic policy 23 Environmental conditions 18 Forecasting 18 Economic development 17 Petroleum law and legislation 17 Energy industries 16 Natural resources 16 Finance 15 less ...