U.S. Environmental Protection Agency, Office of Water, Office of Wastewater Enforcement and Compliance : U.S. Agency for International Development , Office of Research and Development, Office of Technology Transfer and Regulatory Support, Center for Environmental Research Information[1992]Manual
U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Reseach Information , Office of Water, Office of Wastewater Enforcement and Compliance[1992]Manual
