Schullery, P. (2001). America's national parks: The spectacular forces that shaped our treasured land (1st American ed.). DK.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSchullery, Paul. America's National Parks: The Spectacular Forces That Shaped Our Treasured Land. 1st American ed. London : New York: DK, 2001.
एमएलए (8वां संस्करण) प्रशस्ति पत्रSchullery, Paul. America's National Parks: The Spectacular Forces That Shaped Our Treasured Land. 1st American ed. DK, 2001.
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