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Periodical. Sagan, Carl, Joseph Veverka, Paul Fox, Russell Dubisch, R. French, P. Gierasch, Lynn Quam, Joshua Lederberg, Elliott C. Levinthal, R. B. Tucker, B. Eross, and J. B. Pollack. "Variable Features on Mars, 2, Mariner 9 Global Results." Journal of Geophysical Research 78, 20 (10 July 1973): 4163-4196. Article. 34 Images.. Journal of Geophysical Research. Lederberg UI. P222