1. Emerging Patterns of Urban Growth and Travel;Ganz,1968
2. The Need for a Pollution-Free Vehicle;Sweet;Journal of the Air Pollution Control Association,1968
3. Hybrid Power Systems for Vehicles;Hoffman,1967
4. G.A. Hoffman, The Electric Automobile, Scientific American, Vol. 215, No. 4, pp. 34–40.
5. Electrochemical Vehicle Powerplants;Swinkels,1968