Author
Geological Survey (U.S.)
2,698
Library of Congress Congressional Research Service
2,321
American Society for Testing and Materials
1,330
ASTM International
1,260
United States Environmental Protection Agency
1,105
United States Environmental Protection Agency. Office of Research and Development
821
SpringerLink (Online service)
785
United States Environmental Protection Agency. Office of Air Quality Planning and Standards
776
United States Congress. Senate. Committee on Environment and Public Works
491
United States General Accounting Office
438
Films for the Humanities & Sciences (Firm)
386
Films Media Group
372
California Air Resources Board
350
United States
339
United States Federal Water Pollution Control Administration
318
United States Congress
316
National Water-Quality Assessment Program (U.S.)
293
Library of Congress Congressional Research Service. Resources, Science, and Industry Division
285
United States National Air Pollution Control Administration
283
Industrial Environmental Research Laboratory (Research Triangle Park, N.C.)
282
United States Environmental Protection Agency. Office of Water
280
California Environmental Protection Agency Air Resources Board. Research Division
258
United States Public Health Service
252
ebrary, Inc
237
Adam Matthew Digital (Firm)
235
United States Congress. Senate. Committee on Public Works
201
United States Department of Energy
201
United States National Commission on Air Quality
188
United States Environmental Protection Agency. Office of Research and Monitoring
185
Air and Energy Engineering Research Laboratory
179
United States Congress. Senate. Committee on Public Works. Subcommittee on Air and Water Pollution
174
United Nations Environment Programme
173
Organisation for Economic Co-operation and Development
164
United States Government Accountability Office
163
United States Congress. House. Committee on Public Works
159
United States Environmental Protection Agency. Emission Standards Division
149
United States Congress. House. Committee on Transportation and Infrastructure. Subcommittee on Water Resources and Environment
145
Industrial Environmental Research Laboratory (Cincinnati, Ohio)
144
United States Environmental Protection Agency. Emission Standards and Engineering Division
144
ProQuest (Firm)
142
Environmental Sciences Research Laboratory
132
United States Division of Air Pollution
132
Ḳol Yiśraʼel
130
Robert S. Kerr Environmental Research Laboratory
116
United States Environmental Protection Agency. Office of Transportation and Air Quality. Assessment and Standards Division
116
United States Environmental Protection Agency. Office of Air and Radiation
112
Air Pollution Technical Information Center
109
United States Congress. House. Committee on Transportation and Infrastructure
109
World Health Organization
107
United States Division of Water Supply and Pollution Control
105
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