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.
Lua i Stíl Chicago (17ú heag.)Sparks, R. S. J., agus 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.
Lua MLA (9ú heag.)Sparks, R. S. J., agus 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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