Enger, E. D., & Smith, B. F. (2004). Environmental science: A study of interrelationships (Ninth edition.). McGraw-Hill Higher Education.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रEnger, Eldon D., और Bradley Fraser Smith. Environmental Science: A Study of Interrelationships. Ninth edition. Boston: McGraw-Hill Higher Education, 2004.
एमएलए (8वां संस्करण) प्रशस्ति पत्रEnger, Eldon D., और Bradley Fraser Smith. Environmental Science: A Study of Interrelationships. Ninth edition. McGraw-Hill Higher Education, 2004.
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