CCOHS Canadian Centre for Occupational Health and Safety
CDC Centers for Disease Control and Prevention 
DOE U.S. Department of Energy
EPA U.S. Environmental Protection Agency
The Federal Register
NASA National Aeronautics and Space Administration
NIH National Institutes of Health
NIOSH National Institute for Occupational Safety and Health
NSF National Science Foundation
OSHA Occupational Safety and Health Administration
U.S. Department of Health and Human Services
U.S. Patent and Trademark Office