APA (7 वां संस्करण) प्रशस्ति पत्र
Environmental Law Institute & ebrary, Inc. (1999). Plumbing the future: Sewage infrastructure and sustainability in western Pennsylvania. Environmental Law Institute.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र
Environmental Law Institute और Inc ebrary. Plumbing the Future: Sewage Infrastructure and Sustainability in Western Pennsylvania. Washington, D.C.: Environmental Law Institute, 1999.
एमएलए (9वां संस्करण) प्रशस्ति पत्र
Environmental Law Institute और Inc ebrary. Plumbing the Future: Sewage Infrastructure and Sustainability in Western Pennsylvania. Environmental Law Institute, 1999.
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