Koomey J, Akbari H, Blumstein C, Brown M, Brown R, Calwell C, et al. Defining a standard metric for electricity savings. Environmental Research Letters. 2010;5(1):014017. Abstract
Kammen DM, Lemoine D, Arons S, Hummel H. Cost-Effectiveness of Greenhouse Gas Emission Reductions from Plug-in Hybrid Electric Vehicles. In: Brookings-Google Plug-in Hybrid Summit . Brookings; 2008. Abstract