Fractional Distillation of petroleum in refinery

1. http://science.howstuffworks.com/environmental/energy/oil-refining4.htm
2. https://en.wikipedia.org/wiki/Fractional_distillation
3. http://www.pearsonlongman.com/technicalenglish/pdf/level2/level2_unit8.pdf
4. http://www.citycollegiate.com/petroleum_IX.htm
5. http://www.docbrown.info/page04/OilProducts02.htm