1. Number of motor vehicles registered in the United States from 1990 to 2016;U.S. Department of Transportation (US DOT), Federal Highway Administration,2018
2. Transitions to alternative vehicles and fuels;National Research Council,2013
3. Cradle-to-grave lifecycle analysis of U.S. light duty vehicle-fuel pathways: a greenhouse gas emissions and economic assessment of current (2015) and future (2025-2030) technologies;Elgowainy,2016
4. Global EV outlook 2018, towards cross-model electrification;International Energy Agency,2018