1. Sanna , L. 2005 http://mydocs.epri.com/docs/CorporateDocuments/EPRI_Journal/2005-Fall/1012885_PHEV.pdf
2. Plug-in hybrids on the horizon - building a business case;Douglas;Journal of Electric Power Research Institute (EPRI),2008
3. Vehicle-to-grid power implementation: from stabilizing the grid to supporting large-scale renewable energy;Kempton;Journal of Power Sources,2005
4. http://www.eia.doe.gov/cneaf/electricity/epa/figes1.html 2011