1. BP, BP Statistical Review of World Energy 2018, 67th edn. (London: BP, 2018), available online at www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2018-full-report.pdf.
2. BP, BP Statistical Review of World Energy 2016, 65 edn. (London: BP, 2018), available online at http://oilproduction.net/files/especial-BP/bp-statistical-review-of-world-energy-2016-full-report.pdf.
3. Global Trade Statistic, “Global Trade Information Services”, available online at www.worldtradestatistics.com/English/GTIS.html.
4. World Energy Outlook 2010
5. OPEC, Annual Statistical Bulletin 2016 (Vienna: OPEC, 2016), available online at www.opec.org/opec_web/static_files_project/media/downloads/publications/ASB2016.pdf