U.S. Environmental Protection Agency (EPA)
EPA's Office of Transportation and Air Quality (OTAQ)
California Air Resources Board (CARB)
China's Ministry of Environmental Protection
Environment Canada
European Commission's Environment Directorate-General
Germany's EPA
New York State Energy Research and Development Authority (NYSERDA)
Northeast States for Coordinated Air Use Management (NESCAUM)
State Environmental Protection Administration of China (SEPA)
Association for Emissions Control by Catalyst (AECC)
Diesel Technology Forum
DieselNet
Manufacturers of Emission Controls Association (MECA)
Society of Automotive Engineers(SAE)
Institute of Clean Air Companies(ICAC)