Kirk, E. (2011). Human footprint: Everything you will eat, use, wear, buy, and throw out in your lifetime. National Geographic.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रKirk, Ellen. Human Footprint: Everything You Will Eat, Use, Wear, Buy, and Throw Out in Your Lifetime. Washington, D.C.: National Geographic, 2011.
एमएलए (8वां संस्करण) प्रशस्ति पत्रKirk, Ellen. Human Footprint: Everything You Will Eat, Use, Wear, Buy, and Throw Out in Your Lifetime. National Geographic, 2011.
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