United States. Environmental Protection Agency. Office of Research and Development, Municipal Environmental Research Laboratory, Clark, R. M., & Stevie, R. G. (1979). Managing small water systems: A cost study. Municipal Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency ; Springfield, Va. : NTIS [distributor].
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)United States. Environmental Protection Agency. Office of Research and Development, Municipal Environmental Research Laboratory, Robert Maurice Clark, و Richard G. Stevie. Managing Small Water Systems: A Cost Study. Cincinnati, Ohio: Municipal Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency ; Springfield, Va. : NTIS [distributor], 1979.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)United States. Environmental Protection Agency. Office of Research and Development, et al. Managing Small Water Systems: A Cost Study. Municipal Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency ; Springfield, Va. : NTIS [distributor], 1979.