Spellman, F. R. (1999). Environmental science and technology: Concepts and applications. Rockville, Md: Government Institutes.
शिकागो स्टाइल उद्धरणSpellman, Frank R. Environmental Science and Technology: Concepts and Applications. Rockville, Md: Government Institutes, 1999.
एमएलए उद्धरणSpellman, Frank R. Environmental Science and Technology: Concepts and Applications. Rockville, Md: Government Institutes, 1999.
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