Schäfer, R. (2007). Climate, Water Supply, Energy and Food: Challenges for the future. Topos.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSchäfer, Robert. "Climate, Water Supply, Energy and Food: Challenges for the Future." Topos 2007.
एमएलए (8वां संस्करण) प्रशस्ति पत्रSchäfer, Robert. "Climate, Water Supply, Energy and Food: Challenges for the Future." Topos, 2007.
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