1. a General Motors R&D Center , Warren , MI , USA
2. b California Air Resources Board , Sacramento , CA , USA
3. c Federal Highway Administration , Baltimore , MD , USA
4. d Caterpillar, Inc. , Mossville , IL , USA
5. e U.S. Environmental Protection Agency , Ann Arbor , MI , USA
6. f South Coast Air Quality Management District , Diamond Bar , CA , USA
7. g Toyota Technical Center , Ann Arbor , MI , USA
8. h Marathon Oil Company , Findlay , OH , USA
9. i Coordinating Research Council , Alpharetta , GA , USA
10. j National Renewable Energy Laboratory , Golden , CO , USA