Sparks, R. S. J., & Hawkesworth, C. J. (2004). The state of the planet: Frontiers and challenges in geophysics. American Geophysical Union International Union of Geodesy and Geophysics.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSparks, R. S. J., और C. J. Hawkesworth. The State of the Planet: Frontiers and Challenges in Geophysics. Washington, DC, [S.l.]: American Geophysical Union International Union of Geodesy and Geophysics, 2004.
एमएलए (9वां संस्करण) प्रशस्ति पत्रSparks, R. S. J., और C. J. Hawkesworth. The State of the Planet: Frontiers and Challenges in Geophysics. American Geophysical Union International Union of Geodesy and Geophysics, 2004.
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