Heller, R. L. (1979). Earth science (2d ed.). Webster Division, McGraw-Hill.
Cita Chicago Style (17a ed.)Heller, Robert L. Earth Science. 2d ed. New York: Webster Division, McGraw-Hill, 1979.
Cita MLA (9a ed.)Heller, Robert L. Earth Science. 2d ed. Webster Division, McGraw-Hill, 1979.
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