4World Oil and Gas Review 2010[R/OL]. 2010. http://www.eni,com/og/attachments/ unico-og-def-con-cover.pdf.
5World Oil and Gas Review 2008[R/OL] 2008. http://www, eni.com/it_lT/ attachments/cultura-energia/analisi.../ wogr2008.pdf.
6JAZAYERI S, KERAMATI S A. An analysis of crude oil price differentials and investment implications[C/OL]. 9th lIES International Conference, Tehran, Iran, 2004. http://www.iies.org/ le/9th_Jazayeri.pdf.
7BRIDJANIAN H, KHADEM SAMIMI A. Bottom of the barrel, an importantchallenge of the petroleum refining industry [J]. Petroleum & Coal, 2011,53 (1):13-21.
8任宁宁.中国石化进口高硫原油加工量增长17%[N].中国石化报20l1-01-06.
9U.S. Energy Information Administration (EIA). EO.B. Costs of Imported Crude Oil by API Gravity [R/OL]. (2011) http:// www.eia.gov/dnav/pet/pet_pri_imc 3_k_m. htm.
