. . . . . . . . . "Oil in the 21st century : issues, challenges and opportunities" . . . . "Aufsatzsammlung" . . . . . . . . . . . . . . . . . . . . "Oil in the 21st Century : issues, challenges and opportunities" . . . . . . . . . "Oil in the 21st century issues, challenges and opportunities"@en . . . . . . . . . . "Fonts d'energia." . . "Petroli Aspectes ambientals." . . "Welt" . . "Pétrole Aspect de l'environnement Prévision." . . "Petroli Indústria i comerç." . . "Petroli." . . "Pétrole Réserves Prévision." . . "Petróleo Industria." . . "Regenerative Energie" . . "Ropa naftowa aspekt środowiskowy prognozy." . . "Indústria petroliera." . . "Erdölmarkt." . . "Industrie pétrolière Prévision." . . "Medi ambient." . . "Klimaveränderung" . . "Mineralölwirtschaft" . . "Ropa naftowa rezerwy prognozy." . . "Comerç." . . "1980-2020" . . "Erdölvorkommen" . . "Production (economics)" . . "Petrologia." . . "Ropa naftowa produkcja i handel prognozy." . . "Energiesparen" . . "Ölpreis" . . "Erdölförderung" . . . .